Baghdad, Iraq ? U.S. warplanes bombed suspected insurgent positions Monday in a restive slum of the Iraqi capital, and hospital officials said 10 people, including civilians, were killed.

The airstrikes in Baghdad’s Sadr City neighborhood underscored how U.S. forces were stepping up their firepower in their battle against insurgents. Such aerial attacks have become increasingly common in Sadr City, Fallujah and other regions where anti-American militants still exert significant control.

The strikes also raise questions about whether a fragile peace agreement with militiamen loyal to radical Shiite Muslim cleric Muqtada al-Sadr will hold. Tensions have rising in recent days between al-Sadr followers and U.S. forces in Sadr City and in the holy city of Najaf, south of Baghdad, where the two sides ended a bloody standoff in August.

Insurgents on Monday continued their attacks against U.S. soldiers and Iraqi security forces. Seven Iraqi National Guard members were killed in two car bombs: Four died in a blast in Mosul, and near Fallujah, another explosion killed three others at a checkpoint, police officials told The Associated Press.

In September alone, 34 car bombs have been detonated in Iraq, the highest monthly tally since the war began in March 2003, U.S. military officials said.

More Americans killed

Two U.S. soldiers died Monday. In Balad, north of Baghdad, a 1st Infantry Division soldier was killed when insurgents opened fire on his patrol, which was responding to a traffic accident that had killed another U.S. soldier earlier.

The two deaths brought the number of U.S. soldiers killed in Iraq this month to 77, according to a compilation of Pentagon press releases by globalsecurity.org, making September the fourth-deadliest month for American forces since the invasion was launched. At least 1,049 U.S. military deaths have occurred since the start of the war, according to a Pentagon tally Monday.

With Iraqi parliamentary elections set for January, U.S. military officials are planning to accelerate efforts in the coming months to crack down on insurgents and restore peace.

Secretary of State Colin Powell said Sunday that a “major thrust” of U.S. efforts in Iraq in the near future would be to eliminate “no-go” areas where U.S. and Iraqi government forces and aid agencies could not freely enter. The air attack in Sadr City early Monday was part of the new effort.

U.S. Army soldiers guard a rooftop stronghold Thursday in the Sadr City section of Baghdad, Iraq. Six months after the area erupted in rebellion, U.S. forces are launching a renewed campaign to wrest control from radical Muslim cleric Muqtada al-Sadr and his al-Mahdi Army and convince residents that ditching the insurgents will lift them out of dire poverty.

U.S. officials said they killed four insurgents and destroyed several enemy positions in Sadr City with a “precision strike” on “positively identified targets.” Witnesses said the attacks began about 1 a.m. and lasted several hours.

Sabah Abaas, an emergency room medical assistant at Jawader Hospital, reported 10 fatalities and 71 injuries, including some women and children.

U.S. officials called reports of civilian casualties “suspect” but said they would investigate the claims.

Hostages freed

In other developments Monday, kidnapped Iranian diplomat Faridoun Jihani was freed, Iranian Embassy officials said in a statement. Jihani, who worked in the Iranian consul in the city of Karbala, south of Baghdad, was abducted Aug. 4 by a group calling itself the Islamic Army of Iraq while driving between the capital and his workplace.

And Jordan’s King Abdullah II said two female Italian aid workers who were abducted and reported killed are alive. Negotiations for their release are continuing, he said.

An estimated 140 foreigners have been abducted in Iraq, including British businessman Kenneth Bigley, whose fate remains unclear.