BAGHDAD, Iraq - A suicide bomber killed four civilians in a crowd outside a police station Wednesday in the northern Iraqi city Tal Afar, police said.

People look at the wreckage of a car bomb in the town of Mahmoudiyah, Iraq, 30 kilometers (20 miles) south of Baghdad, Wednesday Jan. 10, 2006. Two car bombs exploded almost simultaneously Wednesday near a gas station in Mahmoudiya, about 30 kilometers (20 miles) south of Baghdad, killing two civilians and setting several cars on fire, police said. [AP]

At least 12 people were also injured by the blast when the bomber walked into a crowd of people gathering outside the building about 90 miles east of the Syrian border, an officer said on condition of anonymity because he was not authorized to speak to the media.

Around the same time, another suicide bomber targeted the convoy of Tal Afar's mayor. A child was killed and four other people were wounded in that attack, including the mayor's driver, said Mosul police Brig. Abdel-Karim Khalaf. The mayor survived, he said.

Also Wednesday, two bombs exploded almost simultaneously near a gas station in Mahmoudiya, about 20 miles south of Baghdad, killing two civilians and setting several cars on fire, police said.

Police also said a bomb went off in Baghdad's central Karradah neighborhood, wounding a traffic policeman. A parked car bomb also exploded at the center of Kirkuk, 180 miles north of Baghdad, but there was no immediate word on casualties.

On Tuesday night, four members of a family died when their house in Baghdad's Sadr City section was destroyed. Police initially said the attack was from two mortar shells, but later a police official and witnesses said the home was fired on by US aircraft. The official spoke on condition of anonymity because of security concerns.

The US military had no immediate comment.

Sadr City is the largest Baghdad enclave of Iraq's Shiite majority, and a base for the Mahdi Army, a militia led by anti-US cleric Muqtada al-Sadr. Many mortar and rocket attacks have been launched from the outskirts of Sadr City, and US troops have been conducting raids on homes there in recent weeks.

Just south of Baghdad, gunmen shot dead two workers fixing a water pipe damaged by saboteurs a month earlier, a police colonel said.

The workers were killed Tuesday in Madain, about 14 miles southeast of Baghdad, and their bodies were removed from the scene on Wednesday.

Asked if police caught the killers, the colonel, who refused to give his name, said: "With deep regret, the area is full of orchards and it is difficult to carry out raids here." He added that such an operation would require armored vehicles and aircraft, which the Iraqi police do not have.

In Mosul, 225 miles northwest of Baghdad, four Iraqi soldiers were injured Tuesday night when a roadside bomb exploded next to their patrol, police said.