According to Reuters, two witnesses said that the explosion appears to have been a rocket attack.

TV footage showed black smoke rising in the area.

TOLOnews reported a rocket hitting a house in the Khawja Bughra area near the airport, citing eyewitnesses and social media footage.

There was no immediate word on any casualties.

Suicide bomb threats hung over the final phase of the US military’s airlift operation from Kabul Sunday, with President Joe Biden warning another attack was highly likely before the evacuations end.

More than 112,000 people have fled Afghanistan via the massive US-led evacuation since the Taliban movement swept back into power a fortnight ago, and the operation is winding down despite Western powers saying thousands may be left behind.

What had already been a chaotic and desperate evacuation turned bloody on Thursday when a suicide bomber from the local chapter of the Daesh militant group targeted US troops stopping huge crowds of people from entering the airport.

More than 100 people died in the attack, including 13 US service personnel, slowing down the airlift ahead of Biden’s deadline for evacuations to end by Tuesday.

The Pentagon said Saturday that retaliation drone strikes had killed two “high-level” Daesh militants in eastern Afghanistan, but Biden warned of more attacks from the group.

“The situation on the ground continues to be extremely dangerous, and the threat of terrorist attacks on the airport remains high,” Biden said.

“Our commanders informed me that an attack is highly likely in the next 24-36 hours.”

The US embassy in Kabul later released an alert warning of credible threats at specific areas of the airport, including access gates.

Moreover, Al Jazeera’s Charlotte Bellis, reporting from Kabul, said the threat of Daesh remains “very high”.

“We’re told that a [Daesh] attack is ‘highly likely’,” Bellis said.

“I’ve heard that now from a number of people saying definitely do not go to the airport today,” she added.

Al Jazeera reported the Taliban are “particularly concerned about the south entrance of the airport, which is the main entrance protected by the armed group, as well as the northwestern corner of the airport”.

“The Taliban said they were incredibly worried about this [Daesh] threat. They had pushed people back, they had put barbed wire across the road to try and stop anybody getting close and trying to disperse the crowds.”