A firefight broke out in the chaos at Kabul’s Hamid Karzai International Airport early Monday morning as foreign forces continued to assist with evacuations and thousands of Afghans attempted to escape the country taken over by the Taliban a week ago.

One Afghan security personnel was killed and three others wounded when the firefight erupted between Afghan security forces and unknown attackers, the official account of the German Joint Forces Operations Command said in a tweet Monday.

The German military also said that American and German forces involved in the progression of the fighting, but that all of the German forces on the ground were unharmed.

The last week at Kabul’s airport saw images of desperation as mothers handed their babies to foreign soldiers over barbed-wire walls and Afghan civilians clung to airplanes as they took off in desperate attempts to flee their country.

The violence comes as the Joe Biden administration grapples with a torrent of criticism over the fallout of its pullout from Afghanistan.

Biden said Sunday that the U.S. military has evacuated 28,000 people from Afghanistan since Aug. 14, but many thousands of Americans still remain there. The Pentagon said last week that the U.S. military could not ensure safe passage for Americans to Kabul airport, despite several thousand forces now being on the ground.  

On Sunday Biden activated the Civil Reserve Air Fleet, a rarely-used program whereby the Pentagon ordered civilian airlines to provide planes to help accelerate Afghanistan evacuation efforts. The activation is for 18 aircraft from six airlines.

The administration is considering extending the deadline for the complete troop withdrawal beyond its original Aug. 31 date, Biden added.

“Our hope is we will not have to extend, but there are going to be discussions, I suspect, on how far along we are in the process,” he said.

But the Taliban will not extend the Aug. 31 deadline, according to reporting by Reuters citing two anonymous Taliban sources. The sources added that no Western authorities had contacted the group about extending the deadline.

Speaking to press during a visit to Singapore on Monday, Vice President Kamal Harris said, “Right now we are singularly focused on evacuating American citizens, Afghans who worked with us and Afghans who are vulnerable, including women and children.”

“We have a responsibility and we feel a deep commitment to making sure that folks who helped us are safe,” Harris added, saying that there should be a “robust analysis of what happened” later.

Despite her assurances, Afghan staff working at the U.S. embassy in Kabul feel “deeply disheartened” by the U.S.’s evacuation efforts, according to a diplomatic cable seen by NBC News.

The Taliban, with which the U.S. had negotiated a cease-fire agreement, made a series of stunning gains across the country and finally seized the power center of Kabul on Aug. 15, taking essentially complete control of the country within roughly 10 days.

As a consequence, the Islamic extremist militants now have access to billions of dollars worth of American weapons surrendered by the Afghan military, which the U.S. trained and equipped for two decades.

And tens of thousands of Afghans have made desperate attempts to escape, particularly those who worked with U.S. personnel and fear reprisal killings by the Taliban. While Biden has said these Afghans will be supported, advocacy groups say that up to 20,000 remain in the country, unable to board an evacuation flight out due to bureaucratic barriers or lack of safe passage to Kabul airport.