Thousands packed into the Afghan capital’s airport on Monday, rushing the tarmac and pushing onto planes in desperate attempts to flee the country after the Taliban overthrew the Western-backed government. U.S. soldiers fired warning shots as they struggled to manage the chaotic evacuation.

The Taliban swept into Kabul on Sunday after President Ashraf Ghani fled the country, bringing a stunning end to a two-decade campaign in which the U.S. and its allies had tried to transform Afghanistan. The country’s Western-trained security forces collapsed or fled in the face of an insurgent offensive that tore through the country in just over a week, ahead of the planned withdrawal of the last U.S. troops at the end of the month.

In the capital, a tense calm set in, with most people hiding in their homes as the Taliban deployed fighters at major intersections. There were scattered reports of looting and armed men knocking on doors and gates, and there was less traffic than usual on eerily quiet streets. Fighters could be seen searching vehicles at one of the city’s main squares.

Many fear chaos, after the Taliban freed thousands of prisoners and the police simply melted away, or a return to the kind of brutal rule the Taliban imposed when it was last in power.

Read: Taliban seek to project calm as US speeds chaotic evacuation

Wahidullah Qadiri, a Kabul resident, said he hoped for peace after decades of war that have claimed the lives of two of his brothers and a cousin.

“We haven’t seen anything but catastrophes and fighting, so we always live with hope for a long-lasting peace,” he said.

Thousands of others doubted peace would come and raced to Kabul’s international airport. Videos circulating on social media showed hundreds of people running across the tarmac as U.S. soldiers fired warning shots in the air. One showed a crowd pushing and shoving its way up a staircase, trying to board a plane, with some people hanging off the railings.

Massouma Tajik, a 22-year-old data analyst, described scenes of panic at the airport, where she was hoping to board an evacuation flight.

After waiting six hours, she heard shots from outside, where a crowd of men and women were trying to climb aboard a plane. She said U.S. troops sprayed gas and fired into the air to disperse the crowds after people scaled the walls and swarmed onto the tarmac. Gunfire could be heard in the voice messages she sent to The Associated Press.

The U.S. Embassy has been evacuated and the American flag lowered, with diplomats relocating to the airport to aid with the evacuation. Other Western countries have also closed their missions and are flying out staff and nationals.

Read: Concerns over US terror threats rising as Taliban hold grow

By morning, Afghanistan’s Civil Aviation Authority issued an advisory saying the “civilian side” of the airport had been “closed until further notice” and that the military controlled the airspace.

The speed of the Taliban offensive through the country appears to have stunned U.S. officials. Just days before the insurgents entered Kabul with little if any resistance, a U.S. military assessment predicted it could take months for the capital to fall.

The rout threatened to erase 20 years of Western efforts to remake Afghanistan that saw more than 3,500 U.S. and allied troops killed as well as tens of thousands of Afghans. The initial invasion drove the Taliban from power and scattered al-Qaida, which had planned the 9/11 attacks while being sheltered in Afghanistan. Many had hoped the Western-backed Afghan government would usher in a new era of peace and respect for human rights.

As the U.S. lost focus on Afghanistan during the Iraq war, the Taliban eventually regrouped. The militants captured much of the Afghan countryside in recent years and then swept into cities as U.S. forces prepared to withdraw ahead of an Aug. 31 deadline.

Under the Taliban, which ruled in accordance with a harsh interpretation of Islamic law, women were largely confined to their homes and suspected criminals faced amputation or public execution. The insurgents have sought to project greater moderation in recent years, but many Afghans remain skeptical.

Suhail Shaheen, a Taliban spokesman, tweeted that fighters had been instructed not to enter any home without permission and to protect “life, property and honor.” The Taliban have also said they will stay out of the upscale diplomatic quarter housing the U.S. Embassy complex and the posh villas of U.S.-allied former warlords who have fled the country or gone into hiding.

Read: Biden team surprised by rapid Taliban gains in Afghanistan

“The Taliban is seeking to shape the narrative that their accession to power is legitimate — a message for both inside Afghanistan and beyond its borders,” the Texas-based private intelligence firm Stratfor wrote.

“The speed of the Taliban’s final advance suggests less military dominance than effective political insurgency coupled with an incohesive Afghan political system and security force struggling with flagging morale.”

When the Taliban last seized Kabul in 1996, it had been heavily damaged in the civil war that broke out among rival warlords after the Soviet withdrawal seven years earlier. The city was then home to around a million people, most traveling on dusty roads by bicycle or aging taxi.

Today Kabul is a built-up city home to 5 million people where luxury vehicles and SUVs struggle to push through endemic traffic jams. Many of the younger Taliban fighters hail from rural areas without electricity or running water, and are getting their first glimpse of the modern city.