More than 9,000 Afghans who helped Western forces during the 20 year war in the now Taliban-controlled country were stuck at a US base in Germany after a measles outbreak stopped flights to the US.

Another 57 Afghan refugees were waiting in the German city of Giessen after UK customs said they did not meet the entry requirements to fly to the British Isles.

How serious is the measles outbreak?

Authorities stopped flights after four Afghans who landed in the US were diagnosed with measles. They have now been placed in quarantine, White House press secretary Jen Psaki said on Friday.

The US Center for Disease Control then paused all other flights from the Ramstein Air Base where the 9,000 Afghans have been staying, a spokesperson said.

The spokesperson also revealed that there were no cases of measles at the Ramstein base.

Psaki added that Afghans entering the US had to be vaccinated against measles. Officials at Ramstein were discussing the possibility of having the jabs done in Germany before the evacuees take their flights.

Although the Afghans were only supposed to be at the base for a maximum of ten days, there is now no clear date for the restart of flights.

What is happening with the UK-bound Afghans?

British authorities at Frankfurt airport blocked 57 Afghan refugees from getting on a flight to the UK, according to a report on Sunday by German news outlet Welt am Sonntag.

The 20 Afghan men, 19 woman 18 children had arrived via Tashkent in Uzbekistan.

But when the former refugees went to take their flight to the UK from Germany they were told they did not have the required documents,

A Hessian Social Affairs Ministry spokesperson confirmed the report.

She said that "for humanitarian reasons" the 57 people were now staying in Giessen, near Frankfurt. She was unable to say exactly why they were unable to enter the UK.

The British embassy in Germany could not be reached for a comment on the situation.

jc/dj (dpa, AP)