Channel tunnel rail services between Britain and continental Europe resumed on Saturday following a smoke alert on a train, operators said, though delays are expected.
Freight and passenger services through the under-sea link were halted shortly after 0600 GMT on Saturday following a problem on a Eurotunnel shuttle going through the south tunnel.
"There was some smoke emanating from a shuttle transporting trucks. Within 10 minutes all passengers were evacuated into the service tunnel," a Eurotunnel spokeswoman said.
Eurostar passenger services and Eurotunnel freight shuttles have now resumed through the north tunnel.
The Channel tunnel link between southeast England and northeast France has three tunnels: two for rail transport and a smaller service tunnel between them. There are two crossover points between the two main tunnels.
"We are carrying out technical inspections on the shuttle in the south tunnel," a Eurotunnel spokeswoman said.
"Traffic has resumed. Both Eurostars and shuttles are running.
"This has obviously reduced the tunnel's capacity. Once the train can move from the tunnel, traffic will be back to normal. We hope that will happen within an hour."
A Eurostar spokeswoman said: "The traffic is resuming now, we have received authorisation from Eurotunnel. But we expect a knock-on effect on the schedule."
French state rail operator SNCF said nine Eurostar trains were delayed by between 50 minutes and three hours, in all directions: leaving Paris, London and Brussels.