A roadside bomb targeting a police patrol exploded in an outdoor market in Baghdad on Saturday, killing four people and wounding 27, police said.

The victims were all civilians as the explosion missed the police patrol in the al-Sadriya market, police Lt. Ali Mitaab and Lt. Thaer Mahmoud said. The market is in a Shiite-Sunni Arab neighborhood in central Baghdad.

The violence came after Iraqi authorities imposed a four-hour driving ban Friday in Baghdad to prevent reprisals after the killing of Al Qaeda's top deputy in Iraq, Abu Musab al-Zarqawi. A similar ban remains in effect in the volatile Diyala province northeast of Baghdad.

Gunmen in two cars also shot to death a Shiite metal worker and wounded two others in their shop in western Baghdad, police Capt. Jamil Hussein said.

A mortar landed on a house elsewhere in the capital, seriously wounding a 50-year-old woman and a 2-year-old girl, Lt. Maitham Abdul Razzaq said.

A gunfight broke out between Iraqi soldiers and gunmen in the northern city of Mosul, 225 miles northwest of Baghdad, killing two people, including a Syrian truck driver caught in the crossfire, police Abdul-Hamid al-Jubouri said.

He also said gunmen in two cars killed three Shiite butchers near a central bus station in Mosul.