Insurgents set off a series of explosions Wednesday, killing 12 police officers near Kirkuk and hitting a Defense Department convoy as a senior American official visited the capital, the U.S. military and Iraqi police said. Al-Jazeera television broadcast what it said was video of kidnapped American.

The tape showed a man sitting behind a wooden desk as three men pointed their guns toward him. He was holding what looked like a passport and a photo identification. The U.S. Embassy announced the kidnapping of an American citizen on Tuesday. The unidentified American was a contract worker abducted Monday, a spokesman said.

The U.S. military said the Baghdad attack on the U.S. convoy damaged two government SUVs and five civilian cars. It was unclear whether anyone was injured. Al Qaeda in Iraq (search) claimed responsibility.

"A member of our martyrdom seekers' brigade mingled in an American military convoy at the airport road and exploded himself, destroying the infidels," Al Qaeda in Iraq said in an Internet statement. The statement could not be independently verified.

The car bomb was among four explosions that rocked central Baghdad early Wednesday, the military said. A second car bomb did not cause any damage, and the third blast was a "secondary explosion" nearby, the military said.

The military gave no information on the fourth explosion, but twin blasts exploded near a convoy of two U.S. Humvees and a fuel tanker as it made its way through an eastern Baghdad neighborhood, witnesses at the scene said. The truck burned violently and sent up a large plume of black smoke visible across Baghdad.

Near Kirkuk (search), 12 policemen helping to dismantle an apparent decoy bomb were killed by another explosion Wednesday, police said. Three others were injured.

Police Brig. Sarhat Qadir said the explosion 10 miles northwest of Kirkuk occurred as a group of police were trying to cordon off the area. He said the bomb being dismantled was apparently a decoy to draw in more police before the second bomb exploded.

In a separate incident in a suburb of the central city of Hillah, three Iraqi civilians were wounded early Wednesday when unidentified assailants opened fire on passers-by from speeding cars, the Polish-led force responsible for security in the area said.

The violence came as Secretary of State Condoleezza Rice's top deputy, Robert Zoellick (search), arrived in the war-battered capital Wednesday on a one-day visit following a trip to Iraq by Defense Secretary Donald H. Rumsfeld on Tuesday.

"Dimensions of our Iraqi strategy have to have political and economic — complete reconstruction — components as well as a military component," Zoellick told reporters Tuesday while traveling to the Middle East.

His trip, like Rumsfeld's, was kept secret for security reasons until his entourage landed in Baghdad.

On Tuesday, U.S. troops battled arms smugglers and fighters near the Iraqi town of Qaim along the Syrian border, killing nine insurgents, the U.S. military said Wednesday.

No Americans were injured, the U.S. military said.

Hamid al-Alousi, director of Qaim hospital, said his facility had received nine corpses and nearly two dozen wounded in the violence, all believed to be civilians. Residents of a small village just north of Qaim said more than a dozen more people were buried in the area and not taken to the hospital.

It was impossible to verify the claims.

Without providing details, the group Al Qaeda in Iraq, led by Jordanian militant Abu Musab al-Zarqawi (search), claimed responsibility for the Qaim clashes. The claim, posted on the Internet, could not be verified.

U.S. military officials said that two other raids in the area in the last week had resulted in the capture of smugglers who "confessed to bringing weapons, foreign fighters and money for terrorists across the Syrian border into Iraq."

The Iraqi government, meanwhile, claimed to have captured a former member of Saddam Hussein's regime, Fadhil Ibrahim Mahmud al-Mashadani. The government said al-Mashadani was the leader of the military bureau in Baghdad under Saddam and it accused him of being "among the main facilitators of many terrorist attacks in Iraq."

"Al-Mashadani is believed to be personally responsible for coordinating and funding attacks against the Iraqi people," the statement said.

U.S. officials did not have any information.