The Sangatte refugee camp is blamed for the regular intrusions

The train was stopped on the French side of the Channel, four miles from Calais.

Kent police said that two suspected illegal immigrants were arrested by French police.

Trains continued to pass through the second tunnel, but the disruption caused extensive delays.

Passengers faced delays of up to one hour. Freight traffic was harder hit, with delays of up to four hours.

Gang

EWS, the company operating the train, has said the train was halted after Eurotunnel staff spotted asylum seekers on top of containers.

The tunnel has been hit by a string of intrusions by immigrants hoping to enter Britain.

In January, a Romanian gang accused of controlling the train's signals to allow immigrants to jump onto trains was caught by police.

In December last year, hundreds of people stormed the tunnel entrance.

The persistent attempts to access the tunnel have prompted calls for the closure of the Red Cross Sangatte refugee centre near its French entrance. However Eurotunnel's most recent legal attempt to force the camp's closure ended in failure.