At least one enemy fighter opened fire after a suicide bomb was detonated by a main entry gate at Kabul's Hamid Karzai International Airport on Thursday, the Defense Department said.
The Pentagon also corrected its initial statements about the attack on the airport, claimed by the Islamic State-Khorasan, clarifying that there was only one suicide bomber. Initially, military leaders said a pair of ISIS-K suicide bombers struck, one near the airport's Abbey Gate and another by the nearby Baron Hotel.
Army Maj. Gen. Hank Taylor, Joint Staff deputy director for regional operations, said Friday that no second bomb went off near the hotel.
The bomb at the airport's gate was devastating, killing 13 U.S. service members and wounding another 18. The tally of Afghan civilians who were killed or wounded trying to make it into the airport and get out of Afghanistan is not yet complete, but numbers at least dozens, possibly well over 100.
Taylor said the attacker detonated his suicide vest at about 5:48 p.m. local time right outside the gate, one of the airport's primary entrance points.
Another attacker, or attackers, opened fire from a position somewhere north of the gate area, he said, though investigators are still trying to determine what happened.
ISIS-K and the Taliban are bitter enemies and, in recent years, have clashed in Afghanistan. While the Taliban is currently maintaining an uneasy truce with the U.S. as it withdraws, ISIS-K may view attacking the evacuation operation as an opportunity both to bloody the United States and embarrass the Taliban.
Despite the attack, Taylor said, the military's mission to evacuate Americans, Afghans and other civilians continues, though it is still slated to conclude Aug. 31.
"There are more than 5,000 U.S. service members in harm's way, saving as many people as they can," Taylor said. "It's a noble mission. We have seen firsthand how dangerous that mission is. But ISIS will not deter us from accomplishing this mission."
Thursday night, President Joe Biden threatened to retaliate against ISIS-K for its attack.
"We will not forgive," Biden said. "We will not forget. We will hunt you down and make you pay."
Taylor would not detail what actions the military might take against ISIS-K, but said U.S. Central Command has the capabilities it needs.
As of Friday morning, 29 C-17 Globemaster III and six C-130 Hercules transport aircraft had taken off with about 8,500 people over the previous 24 hours according to Pentagon officials. Another 54 flights from allies evacuated 4,000 more. So far, about 111,000 people have evacuated from Afghanistan in total. That includes about 5,100 Americans, with more than 300 departing in the last day.
About 5,400 people remained on the airport grounds as of Friday morning.
Concerns have mounted in recent days that the military, which has to get all of its personnel and equipment out of Afghanistan by the end of Aug. 31, is about to wrap up evacuation flights for civilians.
Taylor said the military will be able to include evacuees on flights out of Afghanistan "until the very end."