The US has warned its citizens to avoid Kabul airport amid concerns about the potential for attacks by Afghanistan’s branch of the Islamic State (IS) group.

A security alert on Saturday told US citizens to stay away due to possible “security threats outside the gates”.

Only those individually told to make the journey by a US government representative should do so, it said, BBC reported.

US defence officials said they were monitoring developments and looking at alternative routes.

No further details were given about the potential threat of an IS attack, and the group has not publicly threatened to carry out attacks in Kabul.

The US advice on Saturday came amid continued chaos outside the airport terminal and reports of people being crushed as thousands attempt to escape from Afghanistan, a week after the Taliban takeover.