Migrants swarmed British-bound vehicles in the French port of Calais on Tuesday after a strike by ferry workers severely disrupted services across the English Channel, shutting down the cross-channel tunnel and stranding thousands of passengers.
The ferry strike diverted vehicles to the Channel Tunnel, causing a massive traffic jam that was exacerbated when strikers entered part of the tunnel and set fires, helping to sow chaos.
Images broadcast on television showed large groups of migrants, most from North Africa and the Middle East, running after slow-moving or stationary trucks and clambering on board in the hope of traveling to Britain through the Channel Tunnel undetected.
The British Foreign Office issued a warning to all drivers along that route to keep their doors locked and secure any unattended vehicles to keep people from illegally entering the country.
"The suspension [of services] meant there were lots of vehicles having to queue on the motorway, and [that] is an invitation to migrants to climb on board," Eurotunnel spokesman John Keefe said.
Keefe said some of the migrants had broken into trucks, threatened drivers and damaged the goods on board in an attempt to get into Britain without papers.
"Pretty much everything they are doing is illegal," he said.
"We will spend most of this evening pulling migrants off trucks … our requirement is to make sure that no one is on board when they go into the tunnel."
The wildcat strike was carried out by MyFerryLink workers who are concerned about job losses.
They blocked ferry traffic during two separate actions on Tuesday - for a few hours in the early morning and then later in the afternoon, Eurotunnel said.
The action caused severe gridlock for vehicles either trying to make their way to the port or onto the Channel Tunnel bound for England, as well as for drivers trying to make French-bound journeys on the English side of the Channel.
Later in the day, the workers also broke into the Eurotunnel terminal, got onto the tracks, threw rubble around and set fire to tires causing huge plumes of smoke, Keefe said.
Eurotunnel trains carry vehicles through the tunnel. Its service was briefly suspended but was running again by evening, with some delays.
However, EuroStar, which runs a high-speed passenger train through the tunnel, said all its services would be suspended until the morning, bringing disruption to passengers trying to board at Paris' Gare du Nord and London's St. Pancras Station.
Ferry traffic resumed from the port by evening following earlier disruptions.
The day's events shone a new spotlight on a migrant camp at Calais, which has swelled to an estimated 3,000 people.
Calais Deputy Mayor Philippe Mignonet told the BBC that it was "hyper critical" to say the migrant situation was Calais' responsibility.
"Calais is not the destination. ... The fact that they wanted to get in trucks, that's because they want to go to England, so that means that England is the magnet," he said. "The English government has got to realize that it is not our responsibility."
"They go through Calais to get to England, and I wish them good luck," he added.