Eurotunnel temporarily suspended services between Folkestone and Calais after more than 100 migrants broke into the French side of the terminal, the company said.
The “organized intrusion” happened at 12:30 a.m. local time Saturday, said John Keefe, Eurotunnel spokesman.
Dozens of migrants attacked security guards and broke into the terminal through an area where fences were being constructed, Keefe said.
He said he couldn’t comment on whether any of the guards were injured. Authorities are working on clearing the area.
The company said passenger traffic is getting restored, but delays are expected. The freight service remains suspended.
Last week, a teenager who may have been trying to reach the UK died after he was hit by a train near the French entrance to the tunnel.
He was reportedly the 11th person who died as a result of incidents around the tunnel.
Eurotunnel authorities have intercepted 37,000 migrants since the beginning of the year, according to the operator.
Folkestone is on the UK side while Calais is in France.