Eurostar trains at Calais 'delayed' by migrants trespassing inside the Channel Tunnel

Eurostar said it was not able to confirm the cause of the delays

Safety fast: a sprinkler system goesinto action as soon as a fire isdetected in the Euro Tunnel (AFP/Getty)

A Eurostar train has been delayed by “desperate” migrants trespassing inside the Channel Tunnel, it has been reported.

The operator confirmed that two of its trains had experienced delays leaving Calais but said that no reason for the hold-up was immediately available. It said the trouble had since cleared.

Sky News’ Europe Correspondent, Mark Stone, wrote on Twitter that he was on a train inside the tunnel. “Train slowed right down,” he said. “We are told 'trespassers' in tunnel. Desperate migrants trying to reach UK.”

It comes three days after a freight train travelling through the tunnel was forced to grind to a halt after a migrant was spotted riding on one of its wagons.

The stopping of the train resulted in long delays for the service, on both sides of the channel.

And it came as another migrant appeared in court accused of walking almost the entire length of the Channel Tunnel from Calais to the UK.

Eurotunnel said that there were delays to services in the direction from Calais to the UK, adding that "due to an incident in the tunnel our passenger service is operating with only one tunnel until further notice".

It later tweeted that there was a wait "of one hour on site and approx 30 minutes at Welcome area" because of an incident "which has now been resolved".