A munitions store belonging to the Afghan National Army inside a key airbase used by U.S.-led forces in Afghanistan exploded on Thursday, wounding at least three local soldiers, witnesses said. The cause of the blast was not immediately known, they said, adding that they heard several loud explosions followed by smoke and fire rising from the base, located at Kandahar airbase in southern Afghanistan, Reuters reported. "There were various types of ammunitions in the dump," one source at the airport said. "They consisted of mortars, artillery rounds and small arms." Kandahar governor Assadullah Khalid confirmed the blast, but said he believed it was started by a cooking gas cylinder. A spokeswoman for the U.S. military in Kabul also confirmed the blast, but said that initial reports indicated it was an accident. The base is on the western outskirts of Kandahar and is used by U.S.-led troops hunting Taliban and other militants in Afghanistan.