When the first mortar shell hit, the recruits cheered defiantly.

They were seated in the bleachers of an indoor basketball court at the Police Sports Club, about 800 prospective members of the new Iraqi police. Among them were four friends -- Jawaad Jabri, Alaa Aboud, Adel Finjan and Raed Sudani -- who later described the scene.

When the second mortar round fell five minutes later, they said, no one cheered. Jabri ran to the top of the bleachers and stared out a window at a smoldering crater. "The next one's for us," he told Aboud. "They're getting a fix on our position."

After another five-minute lull, the third shell struck, shaking the gymnasium, they recalled. A police colonel walked to mid-court, the friends recalled, and announced: "This building is no longer safe. Please exit immediately. Go home to your families."

The four raced out of the gym, carrying suitcases filled with clothes and family photos and worn copies of the Koran. They had begun the day thinking they were about to start an eight-week course that would train them to be Iraqi police officers. Instead, they found themselves still pursuing a goal that had nearly cost them their lives.

A war within a war is playing out across Iraq. On one side are the jobless and underemployed young men who continue lining up to apply for positions in the reconstituted police and National Guard. On the other side are the insurgents working assiduously to kill them.

The nascent Iraqi security forces are the key to U.S. plans for bringing the insurgency under control and ultimately drawing down American troops. As Iraqi forces hit the streets over the next several months, U.S. commanders say, they will help provide the necessary stability for Iraq to hold nationwide elections before the end of January.

But the recruits, almost uniformly poor, have become the primary targets for insurgents seeking to undermine that strategy. Of about 250 Iraqis reported killed over the past two weeks, at least 90, or 36 percent, were new police officers or police and National Guard recruits. In Baghdad, U.S. and Iraqi authorities say they believe the insurgents send suicide bombers to patrol the streets in search of large congregations of recruits.

"We're walking dead men," Aboud said.

Sabah Kadim, a spokesman for the Iraqi Interior Ministry, which oversees the police, said that despite the attacks, young Iraqis continue to apply at a furious rate.

"Word spreads through the community; you don't need any publicity at all," Kadim said. "If we want 100 in an area, 3,000 show up. This is the amazing thing: Without any recruitment drive at all, the numbers are not only doubling but tripling."

Jabri said the phenomenon is easily explained: "Everyone wants jobs, and there really are no jobs but the police."

Jabri and his friends technically are not among Iraq's legions of unemployed. He, Aboud and Finjan work intermittently assembling crates for the U.S. military for $7 a day. Occasionally they buy and sell used cars. Their other friend, Sudani, moves air conditioners, a job that normally ends with the coming of winter, now only weeks away.

The four men, all in their mid to late twenties, have been friends since childhood. Jabri, Aboud and Finjan live on the same street in Khalij, a lower-middle-class neighborhood in south Baghdad where Shiite Muslims, Christians and others live relatively peacefully. Along Masbah Street, hundreds of young jobless men idle away the hours in shops and video arcades.

Sudani lives in Ubeidi, a neighborhood of low-slung brick houses that abuts Sadr City, the Baghdad slum largely controlled by followers of rebellious Shiite cleric Moqtada Sadr. Members of Sadr's militia, the Mahdi Army, are known to operate in Ubeidi.

The dreams of the four close friends are in tatters. Jabri, for example, started business school in the southern city of Diwaniyah but quit one year later after, in succession, his father, Naeem, died in a car accident, his mother, Zahra, died of kidney failure, and his older brother, Ali, was paralyzed when his car passed a bomb as it exploded outside a police academy five months ago.

'I'm the Breadwinner'

Jabri lives with his injured brother in their parents' old house. "Now I'm the breadwinner," he said. "I've got to find some decent work to support my brother."

Sudani, 28, attended art school. He liked to spend hours painting Baghdad's ancient markets and their inhabitants but ultimately stopped. "I couldn't afford the materials anymore," he said.

The four said they have scoured their city looking for jobs. Then, last month, a policeman from Khalij asked Jabri if he and his friends would like to submit applications to become officers. The job paid about $210 a month; it was steady work they could count on, the policeman said.

Jabri and the three others were eager; their families were horrified. Sudani has a 6-month-old daughter, Fatma, but his entire family tried to argue that the job wasn't worth the risk. He finally resorted to lying, telling his wife and parents that he had entered a training course with the Transportation Ministry.

Jabri consulted an older family friend, who pleaded with him that it was too dangerous. Jabri disagreed: "It's better to eat dried bread than no bread at all," he told the man. "I'm a young man. I can't sit around without a job. We have a family. We have a house."

On Sunday, Sept. 12, Jabri, Sudani, Finjan and Aboud showed up with their birth certificates, passports and other identification at the barred front gate of a police command center in Baghdad. The police, fearing infiltrators, set up a desk behind the gate, so dozens of applicants lined up in the street to hand their papers through the iron bars.

"Stay alert," an officer told the crowd. "Don't linger in one place. You'll get bombed."

Early the following morning the applicants were invited back for a brief physical examination and a workout at the Zawra Sports Club. Applicants with tattoos were rejected as probable former convicts. The recruits were asked to do 20 push-ups and run sprints.

They were still working out when a rocket-propelled grenade, clearly aimed at them, struck a wall adjacent to the field and exploded. No one was hurt, but the police cut short the testing. Two officers escorted the recruits to the gate and asked them to return the following morning.

Early that Tuesday, when Jabri, Sudani, Finjan and Aboud returned in Finjan's black Volkswagen Passat, concrete barriers blocked the street. A policeman told them they would have to wait until it was safe to enter.

The four men sat on the sidewalk. It was about 8 a.m. Dozens of recruits were milling around and chatting, some dozing against the barriers. Jabri noticed that nearby shop owners were glancing nervously at the recruits; some were closing their metal shutters, even though it was the morning rush hour.

"Let's get out of here; it's too dangerous," Jabri recalled telling his companions.

A group of eight, including the four friends, walked up the street about 500 yards. Four, including Sudani, broke off to a restaurant to eat breakfast. The other four, including Jabri, went next door to shoot pool.

Insurgents Attack

Jabri said his friends were racking the balls when the room imploded. The ceiling collapsed. The windows shattered. Jabri dropped to the floor and crawled under the pool table, he said, to protect himself from the falling debris.

"I waited a minute, maybe a minute and a half, until everything was quiet," he said. "Then I went to find my friends."

He found Sudani, dazed and covered in blood, in the ruined restaurant. He had been just about to take a bite of his kubba, a meat-filled pastry, when the bomb detonated. A shard of hot metal broke his right thumb, sliced open his index finger and hit him in the mouth, knocking out a front tooth and bloodying his lip.

Jabri guided Sudani to the curb and went to look for others. It was an unimaginable panorama, he said. A recruit named Taha had his right leg nearly blown off; a man was cradling it while he helped Taha away from the scene. Jabri walked back toward the concrete barriers where most of the recruits had gathered. The area was littered with the dead and wounded.

The Iraqi Health Ministry said at least 47 people were killed and 114 injured.

After being treated at the hospital, Sudani went home to his family -- his clothes bloodied, his tooth missing and lip shredded, his gauze-covered arm wrapped in a white sling. He could no longer tell them he was in training at the Transportation Ministry. The bombing had been all over the news.

"They were furious, and they were hysterical, and they were happy at the same time that I was alive," he said.

His father pleaded with him to give up the job. Sudani talked it over with Jabri, Aboud and Finjan. They decided to stick it out.

Asked why, Sudani replied: "Life needs."

So on Sept. 18, the four men stuffed their duffel bags with clothes and other possessions and set out for the Police Sports Club, their families crying as they left. The club was on the other side of Baghdad from the bombing. It sat across from a U.S. military base on Palestine Street, one of the city's busiest arteries.

For security reasons, the recruits had not been told where the training would take place, only that they should show up ready to leave for eight weeks.

Authorities had closed off Palestine Street to vehicles, but this time the recruits were allowed to walk to the sports club on foot. "If we die, we die together," Jabri told his friends.

Sudani entered the gym still bandaged from the bombing.

Inside, it was chaos. It was unclear which of the recruits would be accepted for training. Police officers argued with one another. Finjan said the four men initially were told they had been accepted, but when the list was read, their names were not on it.

Then the mortar shells started landing. The session was canceled and the recruits made their way back into the dangerous streets. The last shell fell in a courtyard just as the four friends got into a taxi.

When Sudani walked back into his home that afternoon, he still didn't have a job, but his family greeted him as if he had returned from the dead.

"God does not want this to happen," he recalled his weeping father telling him. "This is the will of God."

Special correspondent Bassam Sebti contributed to this report.

From left, police recruits Raed Sudani, Adel Finjan and Jawaad Jabri say they still want to become officers despite a campaign of violence against Iraqi security forces and pleas by their family members not to take the risks.