BAGHDAD: Iraqi police say two car bombs have killed at least 17 people in Baghdad's Shiite district of Sadr City. The blasts went off in quick succession Wednesday from parked cars filled with explosives. A police official says at least 17 people were killed and nearly 50 wounded. Sadr City is a former Shiite militia stronghold and is heavily guarded by Iraqi military. An offensive last year broke the control of militias over the district, and the area has been relatively quiet in recent months. The police official spoke on condition of anonymity because he was not allowed to release the information. The blasts come less than a week after bombings claimed more than 150 lives over a two-day span. The American military says a U.S.-Iraqi patrol has been ambushed while distributing grants to Iraqi businesses near the northern city of Kirkuk. Iraqi officials say two civilians were killed when the Americans returned fire, but the U.S. military says those killed were enemy fighters. The shooting comes as tensions have risen over a deadly U.S. raid in southern Iraq that the Iraqi government says violated a security agreement. U.S. spokesman Maj. Derrick Cheng says several people launched grenades and began shooting Wednesday as the patrol was handing out micro-grant money to stimulate small businesses in the town of Riyadh. He says reports indicate "two enemy killed and one wounded." He says one American was also wounded.