UPDATE 1-U.S., Afghan forces come under attack in eastern Afghanistan -U.S. official

U.S. and Afghan forces came under attack in eastern Afghanistan on Saturday, a U.S. official in Kabul said.

Colonel Sonny Leggett, a spokesman for U.S. forces in Afghanistan, said a combined U.S. and Afghan force conducting an operation in Nangarhar province was engaged by direct fire. "We are assessing the situation and will provide further updates as they become available," he said.

Afghan defense sources said it was not clear whether the attack was carried out by the Taliban or any other military group. Taliban sources were not immediately available for comment.