JERUSALEM — Violence between Israelis and Palestinians approached all-out war on Tuesday as rocket attacks on Israeli cities and airstrikes in the Gaza Strip killed dozens, injured hundreds and left thousands of people on both sides cowering under day-long bombardments.

Military officials in both camps girded for the battles to escalate further, with Israel calling up eight battalions of reservists and deploying additional artillery batteries in the communities near Gaza that have become the front line of the confrontation.

Militants from Hamas, which controls Gaza, and the Islamic Jihad group fired more than 500 rockets at towns in coastal and southern Israel, killing at least two in the port city of Ashkelon and one in the city of Rishon LeZion. Israelis across that part of the country, including much of the population of Tel Aviv, hustled into shelters or stairways as air raid sirens sounded again and again. Schools in much of southern Israel were closed.

Hostilities between Israelis and Palestinians escalated on May 11 as each side attacked the other with aerial bombardments. (Reuters)

The onslaught was even fiercer in Gaza, where Israel waged one of its most intense air campaigns since a 2014 war engulfed the sides for more than a month. The Israeli military said it struck more than 500 targets in retaliation for the rocket attacks from Gaza. By Tuesday evening, the Palestinian Health Ministry said the strikes had killed 30 Gazans, including 10 children, and injured about 200 others.

Israeli aircraft attacked targets across much of the 141-square-mile Palestinian enclave, including what the Israeli military said were two tunnels used to launch attacks and apartment buildings housing military commanders.

“We go to great lengths to strike only military targets,” said Israeli army spokesman Jonathan Conricus. “They are in houses, courtyards, near schools and mosques.”

The Israeli military said that at least 15 of those killed were Palestinian military officers or combatants. He said the army would conduct an investigation into reports of children killed and blamed Hamas for embedding weapons and launch sites in civilian areas.

Islamic Jihad acknowledged that two of its commanders were killed in Israeli airstrikes. One, Sameh Fahim Hasham al-Mamlouk, 34, was commander of its missile unit in northern Gaza, the group said.

But images from the Shati refugee camp near Gaza City illustrated the wider impact of airstrikes, showing scenes of destruction after the top floor of a residential building was apparently struck. The building’s concrete roof had collapsed onto the apartment below, where residents were shown picking through rubble.

Just up the coast in Ashkelon, Soumy Santhosh, 32, an Indian home caregiver, had been sheltering with her elderly employer when their house took a direct hit from a rocket launched in Gaza. Santhosh was killed and the older woman critically injured in the blast.

The house had no bomb shelter, and the woman’s daughter, Tzipi Malach, had been on her way to take her mother home with her when the rocket hit. She stood Tuesday in front of her now-demolished childhood home, stunned by the sudden tragedy.

“I’m talking from pain,” Malach said, a disposable mask lowered on her face. “No house remains. I’m so confused.”

There were few signs Tuesday that the conflict would ease quickly. Governments around the world were appealing for restraint on both sides, and Egypt had dispatched a security delegation to Gaza in hopes of brokering a cease-fire, according to local Arab media.

Hamas pledged that it would continue to fire rockets in retaliation for recent Israeli police incursions into Jerusalem’s al-Aqsa Mosque, which is considered Islam’s third-holiest site and is a frequent flash point in the Israeli-Palestinian conflict.

Israeli military spokesman Hidai Zilberman said that the Israeli army has its “foot on the gas” and that attacks on the Gaza Strip are likely to intensify in the coming days.

Israeli Prime Minister Benjamin Netanyahu convened an emergency security meeting Tuesday with Defense Minister Benny Gantz, Army Chief of Staff Aviv Kochavi, domestic intelligence chief Nadav Argaman, National Security Council chief Meir Ben Shabbat and other senior officials in Tel Aviv.

In addition to calling up the eight reserve border police battalions, the Israeli military also got government approval to mobilize 5,000 reservists from various units. Israel said it was also deploying more Iron Dome anti-rocket systems around Gaza. The army said the system had intercepted more than 90 percent of the rockets fired into Israel so far.

The rival bombardments began Monday night after days of clashes in Jerusalem, where tensions have been mounting over the pending eviction of several Arab families from the Sheikh Jarrah neighborhood in East Jerusalem. Near-daily protests in the neighborhood have built up as Israel’s High Court prepares to rule on a decades-long property dispute.

That confrontation intensified in recent days as Ramadan brought large crowds to al-Aqsa and clashes broke out between Palestinians and Israeli police. More than 300 Palestinians were injured Monday.

The protests spread to other Arab areas inside Israel. In the mixed Jewish-Arab city of Lod, Arab protesters threw stones and fireworks at passersby and police early Tuesday. And a man whose identity has not been disclosed opened fire on a group of Arab protesters carrying Palestinian flags. Mussa Hasson, a 25-year-old resident of the city, was shot dead, and four other Arab protesters were injured.

A Jewish man and another unidentified man suspected of involvement in the shooting were taken into police custody.

Hundreds of Arab protesters who had accompanied the wounded to Assaf Harofeh Hospital in central Israel threw stones, vandalized equipment and intimidated Jewish and Arab medical staffers. Staffers moved the injured patients to different parts of the hospital, while Israeli police fired stun grenades to disperse the crowds.

Rubin reported from Tel Aviv. Miriam Berger in Ashkelon, Hazem Balousha in Gaza City and Erin Cunningham in Istanbul contributed to this report.