CHALDOVAR, Kyrgyzstan (AP) - There's no word on the fate of the three crew members who were on board an American military tanker refueling plane that crashed today in the rugged mountains of Kyrgyzstan. The U.S. operates an air base in the Central Asian nation. The base is a key part of the war effort in Afghanistan. If any of the crew members were able to eject from the plane, the search would be complicated by the rough terrain in the region. The U.S. base in Kyrgyzstan says it doesn't have any information on the cause of the crash. But a resident of the area said the plane exploded in flight. He said he was working in a field and heard an explosion, and then looked up and saw flames. He says the plane split into three pieces as it fell. The crash site is near a village about 100 miles west of the base. Pieces of the plane, including its tail, are in a grassy field bordered by mountains.