The Libertines have assured fans that frontman Pete Doherty is "safe" after they were forced to cancel two UK gigs due to an emergency "medical situation".

Fans were told the band would not be going on stage at the Electric Ballroom in Camden, London, on Thursday two hours after the gig was scheduled to start.

The gig was intended to celebrate the band's first album together in nine years, but a spokesman arrived on stage at 11.30pm and said: "Due to an emergency - a medical situation - tonight's show is being postponed."

The Libertines' Facebook page then announced that "due to unforeseen circumstances" a Manchester date at the Ritz was being postponed.

"Peter, Carl, John and Gary apologise whole heartedly to their fans and will reschedule both shows as soon as possible. This will not effect any of The Libertines other commitments," the post concluded.

The band later posted a message to fans confirming that Doherty, who attended rehab in Thailand in November 2014 for substance addiction, was "safe".

"We can assure everyone that Peter is safe. Clearly this is a very private matter in many respects, but we also feel it necessary to let people know he is ok," they posted.