The UK urged the Houthi militia to allow UN inspectors access to a derelict tanker and remove the oil it contains on Thursday.

FSO Safer has been moored 7 km off the coast of Yemen since 1988 and fell into the hands of the Houthis in March 2015.

The UK’s Foreign and Commonwealth Office said the 1.14 million barrels of oil onboard could leak into the Red Sea “if nothing is done” and that the tanker is an “environmental disaster waiting to happen.”

The Houthis have actively prevented international engineers from boarding FSO Safer to carry out essential repairs.

There are fears that the oil it contains will start to seep out as the vessel’s condition deteriorates.