KABUL - A U.S. official says both international troops killed by a man in an Afghan army uniform were Americans.

NATO reported Thursday that the two service members were killed by a man dressed as an Afghan soldier in eastern Afghanistan.

Mohammad Hassan, a local Afghan leader in Nangarhar province, says the shooting occurred outside an American base in the province during a riot against the Qur'an burnings. He says the gunman was an Afghan soldier.

President Barack Obama has apologized for the burning of Qurans and other religious texts earlier this week at Bagram Air Field, north of Kabul. The incident has sparked violent demonstrations across the Muslim nation.