Explosive ISIS attack at the Kabul airport killed scores of people, including both civilians and US troops

• An explosive terrorist attack happened outside the Kabul airport on Thursday.
• The Pentagon said that it was "a complex attack" by ISIS that resulted in 13 US service member deaths and numerous of civilian casualties.
• US officials have warned in recent days of possible terrorist threats to operations at the airport.

An explosive ISIS terrorist attack outside Hamid Karzai International Airport in Kabul killed scores of people, including 13 US service members, the Pentagon said Thursday.

The Pentagon said the attack began with an explosion outside Abbey Gate, where many people have crowded daily trying to get into the airport to escape Afghanistan.

The Pentagon initially reported that there was a second explosion near the Baron Hotel, but the US military corrected the record Friday, explaining that the military believes there was no second explosion. There was only one explosion triggered by a single suicide bomber. There were also gunmen who open fire in the area.

The attack left behind numerous casualties. Pentagon press secretary John Kirby said in a statement on Twitter Thursday "that the explosion at the Abbey Gate was the result of a complex attack that resulted in a number of US & civilian casualties,"

In a follow-up statement, Kirby revealed that multiple US service members were killed.

Gen. Kenneth McKenzie, the head of US Central Command, then announced that 12 US service members were killed and another 15 were wounded. That number was later revised to 13 dead with 18 injured.

In addition to the US service members who were killed or wounded, local health officials told The New York Times on Firday that 170 civilians were killed and at least another 200 were wounded in Thursday's bombing.

The CENTCOM commander told reporters Thursday afternoon that the Islamic State was responsible but stressed that "ISIS will not deter us from accomplishing the mission."

Over the past few days, US officials have expressed serious concerns about possible terrorist activity around the airport. In particular, there have been concerns about ISIS-K, the terrorist group's affiliate in Afghanistan.

President Joe Biden warned of this threat on Tuesday, saying that "every day we're on the ground is another day we know that ISIS-K is seeking to target the airport and attack both US and allied forces and innocent civilians."

The US Embassy in Afghanistan sent out an alert on Wednesday urging US citizens to avoid traveling to the airport due to "security threats" outside the gates.

A senior US official told The New York Times that the embassy security alert was issued in response to "specific" and "credible" threats posed by ISIS-K, a common enemy for both the US and the Taliban.

Attacks by ISIS are expected to continue, McKenzie said Thursday, and the military is preparing for that possibility as operations continue at the airport.

Editor's Note: This post has been updated with additional information from the Pentagon about the attack outside the airport in Kabul.