Eurotunnel has said its services are back to normal after an incident stopped a train under the English Channel on Tuesday afternoon.

The 3.50pm service from Calais to Folkestone was stopped in the tunnel after an alarm sounded on board. The train was carrying 100 vehicles at the time.

Passengers were transferred to a different train through a service tunnel and taken to Folkestone.

Eurotunnel said they were provided with food and drink as the original shuttle was brought out and they were eventually reunited with their vehicles.

Passengers complained of long delays, with some suggesting they were stuck in the tunnels for more than five hours.

Videos on social media showed holidaymakers walking through the alternative tunnel alongside the 31-mile rail route between Britain and France, some with suitcases and dogs.

Travellers in Calais were told to stay away from the terminal until 6am on Wednesday, with pictures showing gridlock at the shuttle terminal late into Tuesday evening.

Eurotunnel has defended the time taken to resolve the incident, saying operations such as this “do take time” but are for the safety of everyone and “must be conducted carefully”.

A spokesman said on Wednesday morning: “All services are back to normal, with no waiting for passengers on site.

“The incident followed an alarm on board a shuttle carrying 100 vehicles.

“The shuttle was brought to a controlled stop and inspected. As a precautionary measure, for their safety and comfort, we transferred the passengers on board to another shuttle, via the service tunnel (which is there for exactly that purpose).

“Operations like this do take time, but they are for the safety of everyone and must be conducted carefully.

“Unfortunately that means other customers can suffer extended crossing times, as was the case last night.

“However, we put on additional departures to try to reduce that as much as possible. By 6am on Wednesday, everyone who was caught up in the incident had been carried across, diversions removed, and we are now back to normal services.

“Whilst some passengers experienced a longer journey than planned, everyone was kept safe at all times.

“We apologise to anyone who got caught up in the incident, but we stress that we will always put customer safety above everything.”