A US military plane has declared a mid-air emergency just minutes after taking off from a Scots airport.

The McDonnell Douglas KC-10A Extender, with callsign ROMA91, took off from Glasgow Prestwick Airport in Ayrshire at around 10.06am on Thursday.

It declared a Squawk 7700 emergency at around 10.12am.

This Is Local London: FlightRadar.comFlightRadar.com

It is not yet known what sparked the emergency call, however a Squawk 7700 is used to identify an aircraft that has a possible issue and enables it to have priority over other air traffic. 

At time of writing, the plane, which is operated by the US Air Force, has circled while travelling over the First of Clyde and looks to be returning to Prestwick Airport.

The Herald has approached the US Air Force for comment.

This is a breaking story and will be updated.