Kabul

US troops were forced to fire warning shots at the Hamid Karzai International Airport in Kabul to prevent crowds of desperate citizens running to board planes as the Taliban took over the Afghan capital city, an official told a global news wire.

"The crowd was out of control. The firing was only done to defuse the chaos," the official was quoted as saying.

Gunfire could be heard in several videos on social media. The desperate scenes include crowds hovering around jets and clambering up staircases.

US troops are in charge at the airport, where they are reportedly prioritising the evacuation of the American Embassy staff on military flights.

The US earlier said that it had evacuated all of its embassy staff to the airport.

There was chaos and confusion at the Kabul airport as thousands of Afghans crowded the tarmac trying to catch a flight out of Afghanistan.

"I feel very scared here. They are firing lots of shots into the air," a witness told a news wire.

Several videos have emerged of people running onto the airport runways and trying to board flights.

There are reports that US flights carrying diplomatic staff out of the country are being prioritised, causing anger and leading to more chaos and confusion.