SAN FRANCISCO, Calif. (KRON) — President Joe Biden and his administration warned of threats posted by ISIS-K just days before the attacks at the Kabul airport in Afghanistan.

On Thursday, U.S. officials said they believe ISIS-K was behind the bombing and gun attacks that killed at least 60 Afghans and 13 U.S. troops.

What is ISIS-K?

ISIS-Khorasan, also known as ISIS-K, is an affiliation of the Islamic State (ISIS).

The Islamic State’s Central Asia affiliate sprang up in the months after the group’s core fighters swept across Syria and Iraq, carving out a self-styled caliphate, or Islamic empire, in the summer of 2014. In Syria and Iraq, it took local and international forces five years of subsequent fighting to roll back the caliphate.

ISIS-K first emerged in 2015, and staged attacks as early as April of that year. The current leader of ISIS-K is Shahab al-Muhajir.

Based east of Kabul in the Kunar and the Nangarhar provinces near the Pakistani border, ISIS-K had anywhere from 1,500 to 2,200 fighters just three years ago, according to a study by the Center for Strategic and International Studies from 2018.

Is ISIS-K related to the Taliban?

The Taliban and ISIS-K are sworn enemies and have been fighting for years.

The Taliban, which took control of Afghanistan earlier this month, has been guarding the Kabul airport where evacuations of Americans and Afghans were taking place.

Unlike the Taliban, whose interest is focused only on Afghanistan, ISIS-K is part of the global IS network that seeks out attacks on western, international and humanitarian targets.

What other attacks are ISIS-K responsible for?

ISIS-K has been blamed for some of the worst atrocities in recent years, including targeting girls, mothers, newborns and nurses.

ISIS-K “continues to pose a threat to both the country and the wider region” and is focused on recruitment, with its core base in small areas of the Kunar and Nangarhar Provinces, a June United Nations report said.

On May 8, ISIS-K attacked a school for girls in Kabul and killed at least 68 people and injured more than 165, most of them girls, according to a Defense Intelligence Agency assessment cited by the inspector general.

In May 2020, ISIS-K attacked a Hazara maternity clinic, killing 24 mothers, newborns and a health care provider.

Biden’s message to ISIS-K

U.S. officials said they view the group as a continuing threat.

While addressing the nation following the deadly attacks Thursday afternoon, President Biden promised to avenge the deaths.

“To those who carried out this attack, as well as anyone who wishes America harm, know this: We will not forgive. We will not forget. We will hunt you down and make you pay,” he said.

He said ISIS-K was to blame for the attacks and said there wasn’t any evidence they colluded with the Taliban.

“We have some reason to believe we know who they are,” he said of the bombers and gunmen involved. “Not certain.”

The president also vowed to complete the evacuation of Americans citizens and others from Afghanistan.

More than 100,000 people have been evacuated so far while as many as 1,000 Americans and many more Afghans are still struggling to get out of Kabul.

Biden said the attacks won’t drive the U.S. out earlier than scheduled.

“Let me be clear, while we are saddened by the loss of life, both U.S. and Afghan, we are continuing to execute the mission,” he said. He said there were about 5,000 evacuees on the airfield Thursday awaiting flights. He said the Taliban have been “useful to work with” and are not suspected in the attacks.

The Associated Press contributed to this report.