Organisers of a coastal marathon have blamed the lack of mobile phone signal after a major search operation had to be launched when a group of runners did not turn up at the finish line.

The runners were taking part in the Norfolk Coastal Marathon between Weybourne and Sea Palling on Saturday but organisers became concerned when 13 of them did not show up at the end of the race.

It proved to be a false alarm however, as they had simply gone home.

A rescue team from Mundesley, two from Happisburgh and the Coastguard worked together to try and find those that went missing.

The search, which started at 5.30pm, ended after an hour-and-a-half when organisers were informed that the runners had decided not to complete the marathon.

Kevin Marshall, director of the race organisers Positive Steps, claimed the error occurred because of the notorious lack of mobile phone signal coverage in north Norfolk.

'There was a few issues with communication at check points because of the lack of mobile phone communication,' he said. 'No one was lost and I cannot stress enough that no one was, at any point, in any danger.

'It was just a delay in communication because of the lack of mobile phone signal.'

Mr Marshall said although there were 'lessons to be learnt', the race had been a 'huge success' with more than 200 runners taking part, many of who finished.

He added: 'The race was a resounding success and a huge achievement.'

Patrick Larke, who described himself as one of the 'missing runners', said he received a call on Saturday evening from HM Coastguard informing him he had been reported missing and a search had been taking place to locate him.

He said: 'Because of an injury I never started the race but I did spectate as my wife was running.

'On the day of the race I went to the registration desk and informed them that I would not be running, the lady on the desk acknowledged and commiserated. I assumed that would be the end of it.

'It is a shame this happened as apart from this it looked like a great event along a beautiful coastline - I hope it won't jeopardise the event returning next year, with appropriate lines of communication in place.'

The cost of the search operation is believed to have cost around £15,000, with £11,250 of that to the RNLI.

Wayne Ellis, coxswain at Mundesley Indendent Lifeboat, said: 'Organisers of the marathon were concerned that the runners did not show up at the finish line.

'We were alerted to reports that they had gone missing between Trimingham and Sea Palling.

'We searched between Bacton and Sidestrand, while Happisburgh lifeboats searched between Sea Palling and Bacton, with the coastguard rescue teams.

'Then at about 7pm we were stood down from Humber Coastguard after hearing that the organisers had found out that the runners were fine and either had just not started or had given up half-way through.'