(Reuters) – U.S. forces helping to evacuate Afghans desperate to flee new Taliban rule were on alert for more attacks on Friday after an Islamic State attack killed at least 92 people, including 13 U.S. service members, just outside Kabul airport.

Some U.S. media said the death toll was far higher in Thursday’s attack, which took place near the airport gates where thousands of people have gathered to try to get inside the airport and onto evacuation flights since the Taliban took control of the country on Aug. 15.

Pentagon spokesman John Kirby said hthe United States believed there are still “specific, credible” threats against the airport.

“We certainly are prepared and would expect future attempts,” Kirby told reporters in Washington. “We’re monitoring these threats, very, very specifically, virtually in real time.”.

U.S. and allied forces are racing to complete evacuations of their citizens and vulnerable Afghans and to withdraw from Afghanistan by an Aug. 31 deadline set by President Joe Biden.

Islamic State (ISIS), an enemy of the Islamist Taliban as well as the West, said one of its suicide bombers had targeted “translators and collaborators with the American army”.

The Pentagon said Friday that the attack was carried out by one suicide bomber, not two as earlier thought.

The number of Afghans killed has risen to 79, a hospital official told Reuters on Friday, adding that more than 120 were wounded. A Taliban official said the dead included 28 Taliban members, although a spokesman later denied any of their fighters guarding the airport perimeter had been killed.

Some U.S. media including the New York Times cited local health officials as saying as many as 170 people, not including the U.S. troops, had died in the attack.

The attack marked the first U.S. military casualties in Afghanistan since February 2020 and represented the deadliest incident for American troops there in a decade.

Biden was already facing strong criticism at home and abroad for the chaos surrounding the troop withdrawal that led to the Taliban’s lightning advance to Kabul.

The attack also underlined the realpolitikfacing Western powers in Afghanistan: Engaging with the Taliban who they have long sought to fend off may be their best chance to prevent the country sliding into a breeding ground for Islamist militancy.

Medical staff in the operating theatres of Kabul’s Emergency Hospital worked through the night treating casualties.

“Everybody is concerned at this moment in Kabul, nobody knows what to expect in the coming hours,” said Rossella Miccio, president of the Italian aid group that runs the hospital.

‘HUNT YOU DOWN’

Biden said on Thursday evening he had ordered the Pentagon to plan how to strike ISIS-K, the Islamic State affiliate that claimed responsibility. The group has killed dozens of people in attacks in Afghanistan in the past 12 months.

“We will not forgive. We will not forget. We will hunt you down and make you pay,” Biden said in televised comments from the White House.

Biden has defended the troop withdrawal, saying the United States long ago achieved its original rationale for invading the country in 2001. The U.S.-led invasion toppled the then-ruling Taliban, punishing them for harboring al Qaeda militants who masterminded the Sept. 11 attacks that year.

General Frank McKenzie, head of U.S. Central Command, said on Thursday that the United States will press on with evacuations despite the threat of further attacks. He said some intelligence was being shared with the Taliban and he believed “some attacks have been thwarted by them”.

The United States said it would continue airlifting people right up to next Tuesday but will prioritize the removal of U.S. troops and military equipment on the last couple of days.

Most of the more than 20 allied countries involved in airlifting Afghans and their own citizens out of Kabul said they had completed evacuations by Friday.

Taliban guards blocked access to the airport on Friday, witnesses said. “We had a flight but the situation is very tough and the roads are blocked,” said one man on an airport approach road.

The pace of flights accelerated on Friday and American passport holders had been allowed to enter the airport compound, according to a Western security official inside the airport.

Another 12,500 people were evacuated from Afghanistan on Thursday, raising the total airlifted abroad by the forces of Western countries since Aug. 14 to about 105,000, the White House said on Friday.

France has held talks with Taliban representatives in recent days in Kabul and in Doha to ease its ongoing evacuations, the foreign ministry said on Friday.

Pakistani officials told Reuters that at the Torkham border crossing, Pakistani security forces had opened fire on a group of people trying to illegally enter Pakistan, adding that two Afghans were killed and two others wounded.

LEFT BEHIND

Those killed on Thursday included two British nationals and the child of a third British national, British foreign minister Dominic Raab said on Friday. The country’s defense minister, Ben Wallace, said the threat of attacks would increase as Western troops got closer to completing the huge airlift.

ISIS-K was initially confined to areas on the border with Pakistan but has established a second front in the north of the country. The Combating Terrorism Centre at West Point says ISIS-K includes Pakistanis from other militant groups and Uzbek extremists in addition to Afghans.

Russia called on Friday for rapid efforts to help form an inclusive interim government in Afghanistan after Thursday’s attack, saying ISIS was trying to capitalize on chaos in the country and endangering everyone.

Up to half a million Afghans could flee their homeland by year-end, the U.N. refugee agency UNHCR said on Friday, appealing to all neighboring countries to keep their borders open for those seeking safety.

There are also growing worries Afghans will face a humanitarian emergency with the coronavirus spreading and shortages of food and medical supplies looming.

Medical supplies will run out within days in Afghanistan, the World Health Organization said on Friday, adding that it hopes to establish an air bridge into the northern city of Mazar-i-Sharif with the help of Pakistan.

(Reporting by Reuters bureaux; Writing by Stephen Coates, Mark Heinrich and Hugh Lawson; Editing by Simon Cameron-Moore and Frances Kerry)