NEW : third minibus bombing of the day injures seven people , including four police . Car bomb at busy produce market kills at least 15 , injures seven , officials say . U.S. troops are slated to pull out of Iraqi cities at the end of June as part of an agreement that will see all American troops leave the country by the end of 2011 . In separate incident , four killed by bomb in parked minibus . Market bomb was at same location hit by double car bombing the day .
NEW : third minibus bombing of the day injures seven people , including four police . Car bomb at busy produce market kills at least 15 , injures seven , officials say . In separate incident , four killed by bomb in parked minibus . Market bomb was at same location hit by double car bombing the day .