A series of bombings and shootings killed at least 22 people in Iraq on Thursday, including a 7-year-old girl and two college professors, police said.

Brig. Gen. Abdul-Karim Khalaf, the director of the Interior Ministry's national command center, vowed to strike back at the spiraling sectarian violence in Baghdad, saying that Iraqi security forces will soon launch campaign searching house-by-house in all areas of the capital to confiscate caches of hidden weapons.

"No house or area will be excluded from this search. All kinds of weapons will be confiscated," he said at a news conference, adding that 40 policemen were killed and 90 wounded in the capital during the last seven days.

The U.S. military confirmed Thursday that another soldier died in fighting the day before, raising to 11 the number of American troops killed in a single day the bipartisan U.S. Iraq Study Group in Washington increase pressure on U.S. President George W. Bush to change his war strategy.

The soldier was shot Wednesday while manning a machine gun nest on the roof of an outpost in Ramadi, 70 miles west of Baghdad, the capital of the volatile Anbar province, according to an Associated Press reporter who was on the scene.

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The death came on the same day that 10 other U.S. troops were killed in four separate incidents in Iraq, a major blow on the same day a high-level panel in Washington recommended gradually shifting U.S. forces from a combat to a training role.

The military also released details about five of the other troops killed on Wednesday, saying they were Task Force Lightning soldiers who were struck by a roadside bomb while conducting combat operations in vicinity of the northern city of Kirkuk. The soldiers were assigned to 3rd Brigade Combat Team, 25th Infantry Division.

The U.S. military gave no further details about identities or the other deaths, pending notification of relatives.

The attacks followed a particularly bloody weekend and raised to at least 31 the number of U.S. troops who have died in the first week of this month. At least 69 troops were killed in November and 105 soldiers were killed in October -- the highest amount for a month since January 2005. At least 2,919 service members have been killed since the war started in 2003, according to an Associated Press count.

Police said fighting involving Sunni Arab insurgents in Ramadi occurred from 4 p.m. Wednesday to 12 noon Thursday. Twelve civilians were killed and nine wounded, a policeman and a hospital official said, speaking on condition of anonymity out of concern for their safety. The U.S. military said it could not immediately confirm that.

In central Fallujah, another city in Anbar province, a car bomb killed two policemen and wounded one, said a policeman, who also refused to give his name for the same reason.

In Mosul, 225 miles northwest of Baghdad, a 7-year-old girl was killed when she was caught in crossfire of fighting between insurgents and policemen, said police Col. Abdel-Karim Khalaf.

At 3 p.m., gunmen opened fire on Mohammed Haidar Sulaiman, a professor at a sports education college, when he was driving in eastern Mosul, killing him, said police Brig. Abdul Karim al-Jubouri.

In Baghdad, a drive-by shooting killed Professor al-Harith Abdul-Hamid, director of the psychology center at the University of Baghdad, as he was traveling to work, said police Lt. Bilal Ali.

Prime Minister Nouri al-Maliki on Tuesday urged university professors and students to ignore a Sunni Arab insurgent group's warnings to avoid class, calling them "desperate attempts." The group had sent e-mails to students and posted signs at schools and mosques in Baghdad, saying students should stay away while it cleanses the campuses of Shiite death squads, according to a statement from al-Maliki's office.

On Thursday, a parked car bomb exploded near a gas station in Karrada neighborhood of downtown Baghdad, killing one civilian and wounding two, said Majeed.

A drive-by shooting in eastern Baghdad killed police Col. Basim Mudim Abdullah and two of his guards who were traveling in a private car and dressed in civilians clothes, said Majeed.

North of Baghdad, in Diyala province, a drive-by shooting killed a civilian, and roadside bomb killed one police officer and wounded another, police said on condition of anonymity to protect their security.

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