A suicide bomb attack outside the Abbey Gate at Kabul’s airport in Afghanistan Thursday killed ten U.S. Marines and injured three others, U.S. officials told Fox News, as the Pentagon confirmed there was also a second blast at a nearby hotel where Americans had previously sheltered.

A U.S. official said the terror attack set off a firefight at Abbey Gate, where last night there were 5,000 Afghans and potentially some Americans seeking access to the airport to flee.

The Pentagon confirmed the initial explosion as well as a second explosion at the Baron Hotel, where Americans have gathered in the past for rescue and evacuation. Secretary of State Antony Blinken on Wednesday had said that up to 1,500 Americans may still be in the country.

The Pentagon later said “a number of U.S. service members were killed in today’s complex attack at Kabul airport.”

“A number of others are being treated for wounds,” Pentagon press secretary John Kirby said in a statement. “We also know that a number of Afghans fell victim to this heinous attack.”

It was not clear the extent of the injuries suffered by the troops, and how many others were hurt in the large crowds that regularly gathered at the airport seeking to flee the Taliban.

The Taliban had moved quickly through the country ahead of the planned U.S. withdrawal at the end of the month, catching the U.S. off guard and leading to chaotic scenes at Kabul airport and a mass evacuation effort. As of Wednesday, 82,300 people had been flown out, including 4,500 U.S. citizens.