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 said. The burning truck sent up a large plume of black smoke visible across the city.

A U.S. soldier was killed Tuesday during clashes in Ramadi, the military said.

Near Kirkuk, 12 policemen gathered to help dismantle an apparent decoy bomb were killed by another explosion Wednesday, police said. Three others were injured.

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

The violence came as Secretary of State Condoleezza Rice's top deputy, Robert Zoellick, 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 said Tuesday while traveling to the Middle East.

His trip, like Rumsfeld's, was kept secret for security reasons.

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. No Americans were injured, it said.

Hamid al-Alousi, director of Qaim hospital, said his facility received nine corpses and nearly two dozen wounded, all believed to be civilians. Residents of a small village just north of Qaim said more than a dozen 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-Qaida in Iraq, led by Jordanian militant Abu Musab al-Zarqawi, 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 over 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.

---

Associated Press writer Liz Sidoti in Baghdad contributed to this report.