The Afghanistan Civil Aviation Authority (ACAA) said on Monday that Kabul airspace had been released to the military and that it advised transit aircraft to reroute, according to a notice to airmen on its website, hastening some airline route switches.
United Airlines, British Airways and Virgin Atlantic had already stopped using Afghanistan airspace after insurgents took control of the presidential palace in Kabul as U.S.-led forces departed and Western nations scrambled on Monday to evacuate their citizens.
ACAA said any transit through Kabul airspace would be uncontrolled and it had advised the surrounding flight information regions that control airspace.
Kabul's flight information region covers all of Afghanistan.
Flight tracking website FlightRadar24 said on its Twitter account that an Air India flight from Chicago to Delhi had changed course and exited Afghanistan's airspace shortly after entering, while a Terra Avia flight from Baku to Delhi was also changing course.
Airlines and governments have paid more attention to the risks of flying over conflict zones in recent years after two deadly incidents involving surface-to-air missiles.
A Malaysia Airlines plane was shot down over eastern Ukraine in 2014, killing all 298 people on board, and an Ukraine International Airlines jet was downed by Iran's military in 2020, killing all 176 passengers and crew.
The US Federal Aviation Administration in July imposed new flight restrictions over Afghanistan for U.S. airlines and other U.S. operators.
The FAA said flights operating below 26,000 feet were prohibited in the Kabul Flight Information Region, which largely covers Afghanistan, unless operating in and out of Hamid Karzai International Airport, citing the risk "posed by extremist/militant activity."
The restrictions do not apply to U.S. military operations.
Other countries, including Canada, Britain, Germany and France had also advised airlines to maintain an altitude of at least 25,000 feet over Afghanistan, according to website Safe Airspace, which tracks such warnings.
Commercial flights set to land in Afghanistan have also been affected by the chaos on the ground. Emirates has suspended flights to Afghanistan's capital, Kabul, until further notice, the airline said on its website.