Baghdad, Iraq ? Two suicide car bombers plowed into a foreign security company convoy in the heart of Baghdad on Saturday, killing at least 22 people — including two Americans — in an attack that left a busy traffic circle strewn with burning vehicles, mutilated bodies and bloodied school children.

Nearly 300 people have been killed in insurgent violence since Iraq’s democratically elected government was sworn in 10 days ago.

Seven government posts remained undecided until Saturday when Prime Minister Ibrahim al-Jaafari said he would submit nominations for six of them to the National Assembly for a vote today.

A Sunni military man, who fled into exile more than 20 years ago and only returned after the ouster of Saddam Hussein, was selected for the defense ministry, members of al-Jaafari’s Shiite-dominated alliance said. The U.S. military is working to train Iraqi forces to take over the battled against the insurgency with an eye to reducing and, eventually, removing the American troop presence.

The U.S. military said the two suicide attackers crashed their explosives-packed cars into a three-vehicle convoy in Tahrir Square, known for its shops and a large statue of Iraqi soldiers breaking through chains to freedom.

At least 22 people were killed, including the two Americans, who were employees of the company that owned the targeted SUVs, the U.S. Embassy said without identifying the company. Three other American civilians were injured in the attack, the embassy said. Hospital officials said at least 36 Iraqis were wounded in the blasts.

Rescue workers lifted injured school girls onto stretchers, including one with bandages wrapped around her neck and blood streaming down her legs. Firefighters fought the blaze, which sent thick black smoke billowing into the sky.

Iraqi policemen arrive after a car bomb exploded Saturday in a commercial neighborhood of central Baghdad, Iraq.

Elsewhere, a U.S. Marine was killed by a bomb in Karmah, 50 miles west of Baghdad, the military said in a statement. As of Friday, at least 1,592 members of the U.S. military had died since the beginning of the Iraq war in March 2003, according to an Associated Press count.

U.S. and Iraqi forces have hit back at insurgents with a series of major raids across the country in recent months.

In a statement issued Saturday, the U.S. command said an April 26 raid netted a suspect described by the U.S. military as a key associate of Iraq’s most wanted militant, Abu Musab al-Zarqawi. Ghassan Muhammad Amin Husayn al-Rawi had helped al-Zarqawi’s al-Qaida in Iraq group arrange meetings and move foreign insurgents into the country.