KABUL (Dispatches) -- A firefight involving Western forces erupted at Kabul airport on Monday when Afghan guards exchanged fire with unidentified gunmen, Germany’s military said, adding to the evacuation chaos as Washington faces pressure to extend its deadline to withdraw.
Thousands of Afghans and foreigners have thronged the airport for days, hoping to catch a flight out after Taliban fighters captured Kabul on Aug. 15 and as U.S.-led forces aim to complete their pullout by the end of the month.
Twenty people have been killed in the chaos at the airport, most in shootings and stampedes in the heat and dust, penned in by concrete blast walls, as U.S. and international forces try to evacuate their citizens and vulnerable Afghans. One person was killed in Monday’s clash, the German military said.
CNN said a sniper outside the airport fired at Afghan guards - some 600 former government soldiers are helping U.S. forces at the airport - near its north gate.

U.S. and German forces were involved in the clash, Germany’s military said. Three wounded Afghan guards were being treated at a field hospital in the airport, it said.
The Taliban have deployed fighters outside the airport, where they have tried to help enforce some kind of order.
On Sunday, Taliban fighters beat back crowds at the airport a day after seven Afghans were killed in a crush at the gates as the deadline for the withdrawal of foreign troops approaches.
The Taliban seized power just over a week ago as the United States and its allies withdraw troops after a 20-year war launched in the weeks after the Sept. 11, 2001, attacks.
The administration of Biden’s predecessor, Donald Trump, struck a deal with the Taliban last year allowing the United Sates to withdraw its forces in exchange for Taliban security guarantees.
President Joe Biden said on Sunday the security situation in Afghanistan was changing rapidly and remained dangerous.
“Let me be clear, the evacuation of thousands from Kabul is going to be hard and painful” and would have been “no matter when it began”,

Biden said in a briefing at the White House.
“We have a long way to go and a lot could still go wrong.”
Biden said U.S. troops might stay beyond their Aug. 31 deadline to oversee the evacuation. But a Taliban leadership official said foreign forces had not sought an extension and it would not be granted if they had.
British Prime Minister Boris Johnson will urge Biden this week to extend the deadline.
The Taliban said Monday they will not agree to an extension of the evacuation mission from Afghanistan “warning of consequences”.
The move would mean “extending occupation” and that is “a red line”, Suhail Shaheen, a member of the Taliban delegation in Doha, the capital of Qatar, said.
Leaders of the Taliban, who have sought to show a more moderate face since capturing Kabul, have begun talks on forming a government, while their forces focus on the last pockets of opposition.
Taliban fighters had re-taken three districts in the northern province of Baghlan which opposition forces briefly captured and had surrounded opposition forces in the Panjshir valley, an old stronghold of Taliban opponents northeast of Kabul.
“The enemy is under siege in Panjshir,” Taliban spokesman Zabihullah Mujahid said on Twitter.
Anti-Taliban leader Ahmad Massoud said on Sunday he hoped to hold talks with the Taliban but his forces in Panjshir - remnants of army units, special forces and militiamen - were ready to fight.
Zabihullah also said the Taliban wanted to “solve the problem through talks”.