Kabul: An explosion went off Thursday outside Kabul’s airport, where thousands of people have flocked as they try to flee the Taliban takeover of Afghanistan. Officials offered no casualty count, but a witness said several people appeared to have been killed or wounded. Western nations had warned earlier in the day of a possible attack at the airport in the waning days of a massive airlift. Suspicion for any attack targeting the crowds would likely fall on the Islamic State group and not the Taliban, who have been deployed at the airport’s gates trying to control the mass of people.Also Read - India Will Soon know Taliban's Capabilities To Run Afghanistan Affairs, Says Taliban Leader Shahabuddin Dilwar

The Pentagon confirmed the blast, with no immediate word on casualties. Adam Khan, an Afghan waiting outside the airport, said the explosion went off in a crowd of people waiting to enter the airport. Khan, who said he was standing about 30 meters (yards) away, said several people appeared to have been killed or wounded, including some who lost body parts. Several countries urged people to avoid the airport earlier in the day, with one saying there was a threat of a suicide bombing. But just days or even hours for some nations before the evacuation effort ends, few appeared to heed the call. Also Read - Over 140 Afghan Sikh Pilgrims Stopped From Coming to India as Taliban Deny Airport Access to Them

Over the last week, the airport has been the scene of some of the most searing images of the chaotic end of America’s longest war and the Taliban’s takeover, as flight after the flight took off carrying those who fear a return to the militants’ brutal rule. Already, some countries have ended their evacuations and begun to withdraw their soldiers and diplomats, signaling the beginning of the end of one of history’s largest airlifts. The Taliban have pledged not to attack Western forces during the evacuation, but insist the foreign troops must be out by America’s self-imposed deadline of Aug. 31. Also Read - Thousands of Desperate Afghans Throng Pakistan Border to Escape Taliban Rule, Video Surfaces | Watch

Overnight, warnings emerged from Western capitals about a threat from Afghanistan’s Islamic State group affiliate, which likely has seen its ranks boosted by the Taliban’s freeing of prisoners during their blitz across the country. British Armed Forces Minister James Heappey told the BBC early Thursday there was very, very credible reporting of an imminent attack at the airport, possibly within hours. Belgian Prime Minister Alexander De Croo said his country had received information from the US and other countries about the threat of suicide attacks on the mass of people.

The acting US ambassador to Kabul, Ross Wilson, said the security threat at the Kabul airport overnight was clearly regarded as credible, as imminent, as compelling. But in an interview with ABC News, he would not give details and did not say whether the threat remained. A while later, the blast was reported. US President Joe Biden has been briefed on the explosion, the White House says.

Late Wednesday, the US Embassy warned citizens at three airport gates to leave immediately due to an unspecified security threat. Australia, Britain, and New Zealand also advised their citizens Thursday not to go to the airport, with Australia’s foreign minister saying there was a very high threat of a terrorist attack. Taliban spokesman Zabihullah Mujahid denied that any attack was imminent in the wake of those warnings.

Earlier Thursday, the Taliban sprayed a water cannon at those gathered at one airport gate to try to drive the crowd away, as someone launched tear gas canisters elsewhere. Nadia Sadat, a 27-year-old Afghan, carried her 2-year-old daughter with her outside the airport. She and her husband, who had worked with coalition forces, missed a call from a number they believed was the State Department and were trying to get into the airport without any luck. Her husband had pressed ahead in the crowd to try to get them inside.

We have to find a way to evacuate because our lives are in danger, Sadat said. “My husband received several threatening messages from unknown sources. We have no chance except escaping. Gunshots later echoed in the area as Sadat waited. There is anarchy because of immense crowds,” she said, blaming the US for the chaos. Aman Karimi, 50, escorted his daughter and her family to the airport, fearful the Taliban would target her because of her husband’s work with NATO.

The Taliban have already begun seeking those who have worked with NATO,” he said. They are looking for them house-by-house at night. Many Afghans share those fears. The hard-line Islamic group wrested back control of the country nearly 20 years after being ousted in a U.S.-led invasion following the 9/11 attacks, which al-Qaida orchestrated while being sheltered by the group.

Senior US officials said Wednesday’s warning from the embassy was related to specific threats involving the Islamic State group and potential vehicle bombs. The officials spoke on condition of anonymity because they were not authorized to discuss ongoing military operations. The Islamic State affiliate in Afghanistan grew out of disaffected Taliban members who hold an even more extreme view of Islam. The Sunni extremists have carried out a series of brutal attacks, mainly targeting Afghanistan’s Shiite Muslim minority, including a 2020 assault on a maternity hospital in Kabul in which they killed women and infants.

The Taliban have fought against Islamic State militants in Afghanistan. But IS fighters were likely freed from prisons along with other inmates during the Taliban’s rapid advance. Extremists may have seized heavy weapons and equipment abandoned by Afghan troops. Amid the warnings and the pending American withdrawal, Canada ended its evacuations, and European nations halted or prepared to stop their own operations.

The reality on the ground is the perimeter of the airport is closed. The Taliban have tightened the noose. It’s very, very difficult for anybody to get through at this point, said Canadian General Wayne Eyre, the country’s acting Chief of Defense Staff Lt Col Georges Eiden, Luxembourg’s army representative in neighboring Pakistan, said that Friday would mark the official end for U.S. allies. But two Biden administration officials denied that was the case. A third official said that the US worked with its allies to coordinate each country’s departure, and some nations asked for more time and were granted it.