The Islamic State has said that it was behind an attack outside the Kabul airport in Afghanistan on Thursday that killed at least 12 U.S. troops and dozens of Afghans attempting to evacuate the country, according to its Amaq News Agency.

The report, which has not been confirmed by U.S. officials, said that a fighter from the Islamic State managed to “penetrate all the security fortifications imposed by the American forces and the Taliban militia around the capital, Kabul,” where he “blew up his explosive belt” as part of the attack.

According to the report, the suicide bomber managed to reach “within no more than five meters” of a large gathering of translators and others linked to U.S. forces stationed at a camp near the airport that “were collecting documents from hundreds of translators and contractors.”

The news agency included a photo of the man identified as the suicide attacker.