Emad Matti, Associated Press
Four of six teens who the Iraq military says were being trained as suicide bombers are lined up at Mosul police headquarters. Their trainer was killed.

BAGHDAD — The Iraqi military on Monday displayed a group of weeping teenagers who said they had been forced into training for suicide bombings by a Saudi militant in the last urban stronghold of al-Qaida in Iraq.

Four of the six boys were lined up for the media at police headquarters in the northern city of Mosul, where they said they had been training for a month to start suicide operations in early June.

The United Nations and the Iraqi and U.S. militaries say they fear that al-Qaida in Iraq is increasingly trying to use youths in attacks to avoid the heightened security measures that have dislodged the group from Baghdad and surrounding areas.

The youths began crying as they were led into the police station.

"The Saudi insurgent threatened to rape our mothers and sisters, destroy our houses and kill our fathers if we did not cooperate with him," one of the youths, who were not identified, told reporters in Mosul, where security forces are cracking down on al-Qaida in Iraq and other Sunni insurgents.

Iraqi soldiers acting on tips found the youths, who ranged in age from 14 to 18, in the basement of an abandoned house on Monday after the Saudi militant who was training them was killed in military operations last week, deputy Interior Minister Kamal Ali Hussein said.

In April, the U.N. said rising numbers of Iraqi youths have been recruited into militias and insurgent groups, including some serving as suicide bombers. It called them "silent victims of the continued violence." There have also been several recent suicide bombings by women.

The U.S. military released several videos in February seized from suspected al-Qaida in Iraq hideouts that showed militants training children who appeared as young as 10 to kidnap and kill. The U.S. military said at the time that al-Qaida in Iraq was teaching teenage boys how to build car bombs and go on suicide missions.

Children have also been used as decoys in Iraq.

Mosul is believed to be al-Qaida in Iraq's last urban base of operations. U.S. and Iraqi forces launched a crackdown this month in the city of nearly 2 million people 225 miles northwest of Baghdad.

The boys were found during a raid in the insurgent stronghold of Sumar, one of the poorest and most dangerous neighborhoods in southeastern Mosul. Police declined to say what charges they could face pending a final investigation.

Kamal said they came from different social backgrounds, one the son of a female physician, another the son of a college professor and four who are member of poor vendors' families.

"They were trained how to carry out suicide attacks with explosive belts and a date was fixed for each one of them," Kamal said.

The U.S. military in northern Iraq said American forces were not involved and had no information about the arrests.

The Iraqi government is trying to assert control over the country with the Mosul offensive and two operations against Shiite extremists, in Baghdad's Sadr City district and the southern city of Basra.

A U.S. soldier was killed and two others were wounded Monday in a roadside bombing in Salahuddin province north of Baghdad. The military announced that another soldier in Baghdad died due to non-combat related causes on Saturday.

The deaths raise to at least 4,082 the number of American service members who have died in Iraq since the war started in March 2003.

Despite a cease-fire by militia fighters loyal to anti-American cleric Muqtada al-Sadr, a roadside bomb struck a U.S. mine-resistant armored vehicle on the southern edge of Sadr City, engulfing it in flames and smoke. The U.S. military said there were no casualties.

A suicide bomber on a motorcycle targeted the house of the local leader of a U.S.-allied Sunni group that has turned against al-Qaida in Iraq, killing four people, including a policeman, two guards and a civilian, and wounding four others, police officials said.

There was a rare roadside bombing near an Iraqi army checkpoint on the heavily guarded road that leads to the Baghdad International Airport. An Iraqi soldier and four civilians were wounded, police said.