At least seven people died when a car bomb exploded at a police station in the northern Iraqi city of Kirkuk on Wednesday, a police spokesman said. Three policemen, two Iraqi soldiers and two civilians died and three policemen were injured, police said. Four soldiers were injured when a car bomb targeted a U.S. convoy on the main road leading to Baghdad International Airport Wednesday morning, the U.S. military said. A U.S. transport helicopter crashed overnight Wednesday near the western Iraqi city of Rutbah, the U.S. military said in Baghdad. The helicopter was transporting soldiers from the 1st Marine Division, which has its headquarters in Falluja. It was not immediately known what caused the crash or whether there were any casualties. Witnesses said the helicopter appeared to have been hit by a surface-to-air missile and exploded on hitting the ground. A second helicopter also came under fire, but was able to reach safety, the witnesses said.