GAZA CITY — The buzz began near midnight on a cool evening last month, a dull distant purr that within moments swelled into the rattling sound of an outboard motor common on the fishing boats working just offshore.

At a busy downtown traffic circle not far from the dormant port, a pickup truck full of police pulled up abruptly. The half-dozen men spilled into the streets.

“Inside, inside,” the officers, all of them bearded in the style favored by the Hamas movement that runs Gaza, urged passersby. Then, pointing to the sky, one muttered, “Zenana, zenana.”

The word is the Arabic term that Gazans have given to Israel’s drone aircraft, a ubiquitous and frightening feature of daily life in this crowded strip of land along the sea. Roughly translated, zenana means buzz. But in neighboring Egypt, a source of Gaza custom and culture, the term is slang used to describe a relentlessly nagging wife.

The light-hearted description belies the drones’ jarring effect on life in Gaza, where 1.6 million Palestinians live in cramped refugee camps, breeze-block houses and high-rise apartments built among olive orchards, palm groves and rolling dunes.

The landscape provides cover for Palestinian militants, who in recent years have fired thousands of rockets — some improvised, some military-grade — into Israel’s besieged southern towns and cities. In the call-and-response conflict between Israelis and Palestinians, the missile fire has repeatedly provoked Israel to invade, its tanks and troops ebbing and flowing from the strip’s broken streets.

But the most enduring reminder of Israel’s unblinking vigilance and its unfettered power to strike at a moment’s notice is the buzz of circling drones — a soundtrack also provided by American drones over Pakistan’s tribal areas and, increasingly, parts of East Africa and the Arabian Peninsula.

The U.S. drone war is largely invisible, carried out in remote regions sometimes beyond the boundaries of America’s battlefields. U.S. officials are reticent to discuss the program, which President Obama has relied on more than his predecessor to kill enemies. Israel’s close-quarters conflict with Palestinians in the relatively accessible Gaza Strip offers a vivid view of the remote-controlled combat, and of the lives of those affected by these tools of modern war.

Israel withdrew its soldiers and settlers from Gaza in the summer of 2005, ending a nearly 40-year presence in a territory its forces occupied in the 1967 Middle East War. In 2006 Hamas gunmen captured the Israeli soldier Gilad Shalit just outside Gaza’s fortified boundary, and since then, Israel has stepped up military operations and aerial surveillance in the strip.

The Palestinian Center for Human Rights says 825 people have been killed by drones in Gaza since the capture of Shalit, who was released in October. Most of those killed, according to the organization, have been civilians mistakenly targeted or caught in the deadly shrapnel shower of a drone strike. By comparison, the New America Foundation says U.S. drones have killed at least 1,807 militants and civilians in Pakistan since 2006.

The Israeli military says it works hard to distinguish between militants and civilians, but that the task is made harder because many of those who fire rockets from Gaza operate amid the fields and houses of residential neighborhoods.

Since 2006, Palestinian rocket fire has killed 16 Israelis, the vast majority of them civilians, including 56-year-old Moshe Ami, who died in a late October rocket strike on the Israeli coastal city of Ashkelon. As the Palestinian rocket arsenal improves, more Israeli cities, from the border town of Sderot to the southern suburbs of Tel Aviv, are sharing Gazans’ everyday fear of attack from the sky.

Across northern Gaza, the response to the arrival of drones overhead is swift and, for some, almost involuntary. Their near-constant presence shapes life beneath them in a thousand ways — from how Islamist militants communicate to the color of exercise clothes chosen for a morning jog to the quality of satellite-television reception.

When the buzz begins, an unemployed tailor in the hilltop village of Ezret Abed Rabbo walks to his window and opens it — one, then another, until the glass in all of them is safe from what he expects to be an imminent blast. The most recent rocked the area in late October when Israel responded with drones and F-16s to the attack on Ashkelon, killing nine Palestinian militants.

“For us, drones mean death,” said Hamdi Shaqqura, a deputy director of the human rights center. “When you hear drones, you hear death.”

Cradle of the drone

About 30 miles north of Gaza, on the edges of Israel’s Ben Gurion International Airport, lies the cradle of the modern drone, a series of cavernous hangars and modest office buildings.

This is the well-guarded campus of Israel Aerospace Industries, a government-owned enterprise that for four decades has been a pioneer in the development of remotely piloted vehicles. One of the drone’s fathers is Shlomo Tsach, the company’s director of advanced programs.

Tsach was part of a small group that created the first surveillance drone in the bitter aftermath of Israel’s 1973 war with Egypt and Syria, where early intelligence failures and battlefield setbacks gave way to a lesson-filled Israeli victory.

Among those lessons was the danger posed to Israeli forces by a lack of real-time intelligence. Israel could not track Egypt’s mobile surface-to-air missile sites, leaving pilots and tank commanders with worthless days-old information on their locations. Tsach recalled a single searing day when Israel lost dozens of planes to anti-aircraft fire.

Before the war was over, Tsach and his crew, working around the clock, had developed a remotely piloted decoy aircraft to draw enemy fire.

Photos from the time show a group of shaggy scientists posing with a small red model aircraft, the decoy that would evolve into the drones of today. Among them was Abe Kerem, who later helped pioneer what became the armed Predator drone used by the United States.

“We tested a lot of very interesting things, but not all of them went up,” Tsach recalled.

By the time Israeli forces pushed into southern Lebanon in 1982, Tsach and his colleagues had developed the Scout, the first unmanned aerial vehicle used on the battlefield. The 120-pound drone could see over hilltops to track mobile artillery, surface-to-air missile batteries and troop movements. Israeli losses diminished significantly.

Not long after the invasion, a group of officers from the U.S. Navy and Marine Corps arrived at the IAI headquarters to talk about drones. The visit marked the beginning of a long collaboration on drone technology between Israeli and U.S. officials, which in recent years has also become highly competitive as companies from the two countries vie for the world’s rapidly growing drone business.

“The United States was not in conflict at the time,” said Tommy Silberring, a retired Israeli colonel who heads IAI’s drone division. “So a lot of the battlefield experience came from here.”

Tsach recalled that “in 1974, when we created the market for drones, no one else wanted it.” Now the IAI hangars are filled with drones of various shapes and sizes — from the Heron TP with a wingspan the size of a Boeing 737’s to the Bird-Eye 65o, which fits in a soldier’s backpack and can be flown from a laptop or smartphone.

Some stay airborne for as long as 40 hours, at altitudes as high as 40,000 feet, while others are tethered to the ground, plugged into an electrical outlet to hover endlessly above any area Israel wants watched. Flying one is as easy as pointing and clicking a mouse on an electronic map, which sends the drone to the spot and instructs it to circle overhead.

Surveillance drones then watch and track, either during the day or at night with heat-detecting radar, or “paint” targets with a laser for F-16 and Apache missile strikes. Armed drones, which Israel, like the United States, keeps away from public view, are fitted with specialized missiles that can be guided by the drone’s own on-board sensors.

“I can see if your car is hot that you were just driving it, if you are smoking a cigarette,” said Lt. Col. R, commander of the drone squadron that flies over Gaza, who spoke on the condition that his full name not be used.

The officer has moved through different parts of the Israel Defense Forces — infantry, helicopters — but he said the drone program is now a highly sought-after branch. “It is the future,” he said, “there is no doubt about that.”

His drones take off from a runway shared with Apache helicopters at the Palmachim Air Force Base along the coast south of Tel Aviv, a site seemingly more suited to a Mediterranean resort than a military installation. A minutes-long flight takes them over Gaza, where they train, test and carry out a growing list of missions.

“The main idea is you tell me what to look for, and I’ll tell you what I see,” he said. “Because Gaza is a very dense urban environment, with civilians and terrorists mixed together, the only way to differentiate is by looking. And this is up to us to do that.”

Fathers and sons

The farming town of Beit Lahiya is a few miles of rough road north of Gaza City, through the trash-strewn streets of the beach camp, a U.N.-run refugee enclave, where on a blustery recent morning fishermen mended nets along the sidewalk.

A new mosque rises on a spit of land above a storm-tossed Mediterranean Sea, a mix of dark blues and greens. Small boys kicked a soccer ball along the dirt roadside, near the burned remnants of a police post bombed days earlier by Israeli military aircraft in retaliation for late-evening rocket fire. A distant Israeli F-16 rumbled overhead.

Gazans use a quick calculus to assess an attack: A destroyed building, such as the small police post, is the result of an F-16. A strike on a sedan, or a group of men clustered at an intersection, is the work of a drone.

Nabil al-Amassi, a mechanic, watched in the summer of 2006 as Israeli tanks rolled into Beit Lahiya in an operation designed to pressure the Hamas leadership to release Shalit in the days following his capture.

A half-dozen armed men stood at the bottom of his sandy street when, suddenly, the drone buzzing above fired. Three of them were killed, including one whose armless torso was carried by screaming survivors from the scene, observed also by a Washington Post correspondent.

That was the start of Amassi’s close relationship with drones. Nearly every day since then, at least one, and sometimes several, have circled above him.

“It’s continuous, watching us, especially at night,” said Amassi, a father of eight children. “You can’t sleep. You can’t watch television. It frightens the kids. When they hear it, they say, ‘It is going to hit us.’ ”

Among his children is Ahmed, a leery 3-year-old who patrols the street in a tiny track suit on fast-moving legs. When he hears the drone arrive, often in the early evening, Ahmed runs to his father and sits deep in his lap, frightened.

“We try to tell them it’s fireworks,” Amassi said.

Two streets away, not far from a grove of olive trees used in the past by Palestinian gunmen to fire rockets into Israel, Naim Dawoud worries about his 27-year-old son Walid.

Gazan men in their mid-20s face twin perils: They draw attention from Islamist militant groups seeking new recruits and from Israeli drones, whose operators seek out Palestinians who have joined the fight.

Short with a stubbly beard, Walid said that when his car breaks down with a drone overhead he leaves it rather than wait for other young men to gather and help.

“These drones — they don’t always know,” he said. “At night, if I hear one, I’ll cancel my plans to see friends. It’s easy — if one is above me, I won’t go out.”

The school on the hill

The Qasteen School sits on a sandy hilltop, a four-story building surrounding a broad courtyard. Murals of a smiling tooth promote dental hygiene, and in the near distance, the bombed-out Palestinian intelligence headquarters looms as a reminder of the dangers outside the campus walls.

In a second-story classroom, Hamza Abu Sultan, a small seventh-grader in a camouflage coat, raised his hand to describe the class reaction to the buzz.

“We feel tense,” he said. “We start to think about when it will hit. We start to think we are somewhere else — no longer in class.”

Ismail Ramadan, the school’s 40-year-old principal, has brought in psychiatrists several times a week to calm the children and explain that the sound of the drones does not mean war is imminent. International charitable organizations partially fund the effort to ease the children’s anxiety.

“They hear the sound and they hold their breath,” Ramadan said.

The head of the Gaza Community Mental Health Program, Eyad Sarraj, said the drones’ noise is something “you can’t escape.” Whether intentional or not, Sarraj said their constant presence induces a sense of helplessness among Gaza’s residents.

“In the back of the minds of everyone here is fear — from the psychiatrist to the student, a sense that something terrible is going to happen,” Sarraj said. “The drones are part of that story. They are part of the conditioning — every time we hear them, we go back to those events of violence and death.”

Entrepreneur’s challenges

Gaza is divided, not only between Fatah and Hamas, the primary political parties in the Palestinian national movement, but between fans of the European soccer giants FC Barcelona and Real Madrid.

Mohammed al-Mabrouk makes a brisk living exploiting this split. He works in the Rannoush sports bar in downtown Gaza City, where patrons pack into the low-ceilinged rooms to sip bitter coffee, smoke water pipes and root for their side in the big games.

None is bigger than “El Clasico,” the Barcelona-Real Madrid match that comes along a few times year. He charges an entrance fee for those games, shown on a handful of high-definition televisions smuggled through the tunnels along Gaza’s southern border with the Sinai. With 220 patrons paying $5 each, the occasions yield a small windfall.

But the take from the November 2010 match was wiped out by a drone, whose looping patrol blurred out much of the match. He reimbursed more than $1,000 in cover charges to a roomful of angry patrons, and since then he has added expensive subscriptions to several other satellite signals. That has done little good. But now Mabrouk can change satellites, flip through channels and show his patrons that he has done all he can. “So at least they know it won’t be better anywhere else,” he said.

His customers still make for the doors at the first telltale signs the picture is fraying, as it did during a recent Chelsea and Liverpool match. For reasons that no one can explain, only Russia Today, an English-language channel promoting Russian views, is resilient enough to survive the drone interference.

“The problem is in the sky,” said Nahed Hammad, who sells satellite dishes from his dimly lit storefront a few doors down, “not in the receiver.”

To some, proof of occupation

Hamdi Shaqqura, the human rights advocate, came downstairs one recent morning in his Gaza apartment to find a note from his daughter, Bisanne, a 22-year-old medical student. She had counted four drones overhead, and she advised her father to skip his morning run.

“But I’m all dressed and I think, ‘I can’t not do this, I can’t change because of this,’ ” Shaqqura recalled. So he set off, only to turn back in fear after about 100 yards, as several drones buzzed above.

“So I get back to my door and I say, ‘Come on, Hamdi, this is Gaza,’ ” he scolded himself, and headed back out. He got as far as he had before when he noticed that, as usual, he was dressed in an all-black track suit — the color of choice for many Palestinian militants. Once again, he headed home, shaking his head at the ridiculousness of the back-and-forth. “It affects every aspect of our lives, all day long,” he said.

For Shaqqura, though, the drones mean something else as well. In his view, they are proof that Israel still legally occupies the strip despite having pulled its soldiers and settlers out.

Israel has argued that it no longer occupies the area, meaning that it is not responsible for the health and welfare of its residents under international humanitarian law. But Israel controls the crossings between Gaza and Israel, the waters off its coast, and the airspace where the drones circle.

“This is the first meaning of the drones,” he said. “Israel’s military may not be on the ground anymore. But they are in the air — looking, always, at every square inch of Gaza. They don’t have to be here in Gaza City to affect every aspect of the lives of Gazans.”

The data collected by the Palestinian Center for Human Rights since the summer of 2006 reflect the up-and-down nature of Israel’s conflict with Gaza. In 2009, the year of the most recent war in Gaza, 315 people were killed in drone strikes, according to the center. The number so far this year is 60.

But Abu Ahmed believes the figures are too high, and that many of the deaths attributed to drones are actually the result of Apache helicopter strikes or F-16 missions, aided by drone surveillance. And as a leader of the Islamic Jihad in Gaza, Abu Ahmed, a big, bearded soldier in the movement’s war against Israel, has a closer-to-the-conflict view of those deaths.

Abu Ahmed is a nom de guerre, and he operates as much as possible away from the view of Israel’s drones.

His office curtains are drawn on a recent sunny day, his walls decorated with posters celebrating the deaths of Islamic Jihad fighters in combat. A ficus plant adds a bit of life in one corner.

In dealing with Israel’s military, Abu Ahmed abides by a basic rule: The higher-tech Israel goes, the lower-tech go the Islamist movement’s foot soldiers.

“When drones are above us, we must meet face to face,” he said. “We must not drive our own cars or take taxis. So we walk. It is obvious when we are being tracked.”

He lists the different names of Israel’s drones — the Hunter and Heron, among others — and cites their range and maximum altitude. A group within the Islamic Jihad works on collecting such information, although so far that intelligence, along with improved weaponry flowing through Gaza’s southern tunnels, has not bolstered the group’s defense against them.

They have never shot one down.

“We advise the people to think of this voice like the noise of rain, something light and humorous and part of life here,” Abu Ahmed said. “But we don’t have the ability to face these drones. The most important thing we can do is to alert our people that they are in an area and how best to avoid them.’’

He paused, resigned, and added, “We will adapt.”

Staff researcher Julie Tate in Washington contributed to this report.