Clashes erupted between gunmen and U.S. and Iraqi forces around a Shiite mosque in western Baghdad before Friday prayers, and two suspected insurgents were killed, the American military said.

Also Friday, the U.S. military announced the death of a Marine in a rocket attack the night before on a base south of the capital. Two others were wounded in the attack on a U.S. base in Mahmoudiya, about 20 miles south of Baghdad, a statement said.

At least 3,315 members of the U.S. military have died since the Iraq war started in March 2003, according to an Associated Press count. The figure includes seven military civilians.

Meanwhile, U.S. forces killed eight suspected insurgents and captured 41 in several raids across Iraq on Friday, the military said.

The small arms fire from around the blue-domed mosque in Baiyaa, a religiously mixed neighborhood in western Baghdad, began at about 9:45 a.m. Friday, and coalition forces supported by U.S. helicopters cordoned off the area and fought back, the statement said.

After killing two insurgents, the soldiers searched nearby buildings, found chemicals believed to be bomb-making materials and detained an Iraqi civilian, the military said. Iraqi soldiers searched the Ali al-Baiyaa mosque, but found no weapons or suspects. The coalition suffered no casualties in the fighting, and damage to the mosque was limited to several small bullet holes, an AP photographer on the scene said.

The military denied claims by witnesses that U.S. helicopters and tanks opened fire on the mosque, killing four people and wounding seven. State TV alleged that a "coalition jet fighter" bombed the mosque, wounding eight Iraqi citizens.

In the holy city of Kufa, 100 miles south of Baghdad, Abdul Hadi al Mohamadawi, a sheik loyal to radical Shiite cleric Muqtada al-Sadr, used his sermon at the Kufa mosque to condemn U.S. forces.

"American forces are conducting an offensive on a mosque in al- Baiyaa, and martyr worshippers are falling," he said. "Let the government see what the occupiers are doing to our people."

On Monday, al-Sadr's six ministers quit the Iraqi Cabinet to protest Prime Minister Nouri al-Maliki's refusal to back calls for a timetable for U.S. withdrawal.

Al-Maliki said Thursday that an "open battle was being waged for control of Iraq," a day after more than 230 people died in the worst spasm of mass killings since U.S. President George W. Bush announced his plan in January to increase American troop levels in Iraq by 30,000.

Three of the five brigades ordered into Iraq by Bush to stem Baghdad violence have arrived, bringing the U.S. forces in the country to 146,000. Officials want the rest in place by June, for a total of 160,000, and U.S. commanders urged patience, saying the nine-week operation was still just beginning. But already it showed holes.

About a week ago, a suicide bomber penetrated several layers of security to hit inside parliament, in the heart of U.S.-guarded Green Zone. An Iraqi lawmaker was killed and the country shaken.

The same day, a truck bomber collapsed a more than 50-year-old bridge, killing 11 people and sending cars careening into the Tigris River below.

At the Pentagon Thursday, a top general predicted the pattern was likely to continue.

"We saw an initial drop in their (militants') activity" after the start of the Baghdad security operation, said Maj. Gen. Michael Barbero, an operations official for the Joint Chiefs of Staff. "And now lately, we've seen an increase — the bridge, this.... It's action on our part and now we're seeing the reaction on their part. And it will be like that until we can defeat these forces."

Al-Maliki said militants had "proven their spite by targeting humanity."

"It is an open battle and it will not be the last in the war we are fighting for the sake of the nation, dignity, honor and the people," he said at a ceremony marking the 50th anniversary of the founding his Islamic Dawa Party.

"This is Iraq. They sabotage and we build and continue the reconstruction," al-Maliki said defiantly.

In addition to a weekly driving ban in Baghdad on Friday, the Muslim holy day, vehicle bans were imposed on the northern cities of Tal Afar and Mosul, authorities said. The ban in Tal Afar, 260 miles northwest of Baghdad, would be in place until further notice, said police commander Brig. Ibrahim al-Jibouri. Intelligence reports indicated car bomb attacks were being planned in the area, he said.

A similar ban imposed in Mosul on Thursday night remained in place Friday, police said.

In other violence Friday:

—Seven suspected Iraqi insurgents were killed after they fired on American troops entering a building near Mahmoudiyah, about 20 miles south of Baghdad, the U.S. military said. Another 15 men were detained. In two more raids in the same city, U.S. forces detained eight suspects and destroyed seven tanks of chlorine, the statement said. Chlorine has been used in car bombs in recent months by Sunni insurgents, mostly in Iraq's western Anbar province.

—In Baghdad, one suspect was killed when U.S. troops entered a building to disrupt a car bomb-making cell, the military said. Six suspects were detained in the raid, and troops uncovered explosives, it said. Two more suspects were also captured in another raid in Baghdad, the statement said.

—In Mosul, 225 miles northwest of Baghdad, ten suspects were detained in two separate raids targeting Al Qaeda members, it added.

—A roadside bomb killed one civilian and wounded three others southeast of Baghdad.

On Thursday afternoon in Latifiyah, about 20 miles south of the capital, gunmen attacked a convoy belonging to the son of Abdul Aziz al-Hakim, head of the country's most powerful Shiite political party, the Supreme Council for the Islamic Revolution in Iraq. Ammar al-Hakim escaped unharmed, but two of his bodyguards and four policemen were wounded in the attack.