Traffic along the Channel Tunnel connecting Britain and France has been disrupted when dozens of migrants attempted to enter restricted areas of the tunnel in Calais, according to officials.
The disruption on Friday night was the latest in a series of incidents involving some 3,000 migrants, mostly from Africa and the Middle East, who are camped around the northern French port in the hope of reaching Britain.
"From 10:30 pm (20:30 GMT), around 150 migrants attempted to enter the platforms," a spokesman for the Pas-de-Calais prefecture in northern France told AFP.
The spokesman said traffic was interrupted, with long queues of cars forming, but it reportedly resumed around two hours later.
The migrants "seek to cross the Channel by any means", a Eurotunnel spokesman said, adding that the tunnel "suffers from attempted intrusions every night".
"We have adapted our transport system to ensure the best level of security and keep our trains running," the spokesman added.
Eurostar, which also runs passenger trains through the tunnel, though not at night, said its services had not been affected.
Calais is one of the front lines in a wider immigration crisis in which European countries are struggling to agree among themselves how to deal with growing numbers of migrants fleeing conflict or poverty.
Many migrants want to get to Britain because they speak English, have family connections or are convinced they stand a better chance of getting a job there.
Around 3,000 migrants are currently camped out around Calais in northern France and are trying to cross the Channel into Britain.
The crisis topped the political agenda again in the past fortnight as ferry worker protests at the port led to many migrants breaking into stationary vehicles.
France and Britain signed an agreement last September, creating a fund of five million euros ($5.6m) per year to help Calais cope with the influx of migrants.
The money was supposed to go to reinforcing security around the port and access to the Channel Tunnel.