BAGHDAD, Iraq (CNN) -- Three U.S. Marines and two interpreters were among 20 people killed Thursday when a suicide bomber attacked a meeting of tribal sheikhs in Iraq's Anbar province, officials said.

Twenty people also were wounded in the attack.

A military statement said the Marines were "killed in action against an enemy force." However, Iraq's Ministry of Interior said they died in the bombing. The military had said earlier that coalition forces were among the casualties in the attack.

The suicide bomber struck the meeting in Karma, a town west of Baghdad, an Interior Ministry official said.

Coalition forces were among the casualties in the attack, which authorities believe was carried out by al Qaeda in Iraq.

The bomber detonated an explosives belt inside the Karma municipal council headquarters, according to police and an Awakening Council leader.

The official said Karma's administrative director, three police officers and three sheikhs were among those killed.

In the northern Iraqi city of Mosul, 18 people were killed and more than 80 wounded in two bombings in the area of a busy market in central Mosul, authorities said.

Gov. Duraid Kashmoula said two Katyusha rockets landed near the provincial building in the crowded market area.

He went to inspect the location, and a parked car bomb detonated 25 meters away when he arrived.

He said he and his security detail escaped uninjured, except one guard who was hit by shrapnel in the stomach. He said most of those injured in the attack were civilians.

The Interior Ministry gave a slightly different account, saying a roadside bomb targeted Kashmoula's convoy. Five of his security detail were wounded.

Moments later, a parked car bomb exploded, killing at least 18 people and wounding 80, the U.S. military said.

An Iraqi police officer was among the dead; the rest were civilians. Of the wounded, nine were police, and the rest were civilians, the U.S. military said.

Elsewhere, coalition troops in central and northern Iraq killed two militants and detained 15 people Thursday, the U.S. military said.

The two deaths occurred near Sharqat, south of Mosul, and one of those killed was an al Qaeda in Iraq cell leader, the military said.

In one of the raids, troops captured two Egyptian men thought to be involved in suicide operations in Abu Ghraib.

In Karbala, a bomb attached to a minibus exploded Wednesday night near the Shiite shrine of Imam Abbas, killing a child and wounding four people, including the driver, a police official said.

The explosion took place about 7:30 p.m. after the minibus was stopped at a security checkpoint, the official said. Iraqi police are investigating. Karbala is about 60 miles (100 kilometers) south of Baghdad.

A U.S. soldier was killed in Baghdad on Wednesday by a bomb attack, the U.S. military reported. The death brings the number of American troop deaths in Iraq since Monday to eight.

In June, there have been 26 U.S. troop deaths in Iraq, still a low total in comparison with previous months of the war. May's death toll of 19 was the lowest monthly total of the war.

In 2007, there were 125 troop deaths in May and 101 in June.

Since the war began, 4,110 U.S. service members have died in Iraq.

CNN's Jomana Karadsheh and Mohammed Tawfeeq contributed to this report.

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