The Taliban are permitting US- and UK-run mercy flights to leave Kabul without jihadi interference, but fears are growing over how long the jihadists will allow the rescue operations to continue - and what happens when they no longer 'consent' to them.    

The US army's General Frank McKenzie is leading 6,000 US troops and 900 British soldiers who are trying to evacuate as many as 50,000 Afghan refugees and thousands of other foreign citizens, including aid workers and diplomats, who live in Kabul.  

For the moment, the Taliban say they are giving 'amnesty' to foreigners who wish to leave. But amid tense scenes at the capital, which fell to insurgents with astonishing rapidity, fears are growing that the tentative calm could fall apart at any moment. 

Vice Admiral Sir Ben Key, who is running the British evacuation operation, told the BBC the UK will be bringing back as many people as it can, as quickly as possible, until either demand is met or 'the security situation means that we're no longer operating with consent'.

But eligible individuals have to make the trip to the airport themselves when called to do so, and the Taliban now control the access points, he added. 

Sir Ben said that his forces face a race against time, and they are 'alive to the uncertainty' of the situation. 

The White House today confirmed that the Taliban had promised that civilians could travel safely to the Kabul airport, but reports of insurgents beating and shooting Afghans trying to enter could rattle the uneasy deal between the country's new rulers and their Western adversaries.