Eurostar travellers face further disruptions after an electrical problem shut down the Channel Tunnel for two hours, a day after a lorry fire forced the closure of the crucial transport link.
Eleven trains - two return services between Paris and London and seven trains between Brussels and London - were cancelled.
Eurostar services had only just resumed after being suspended on Saturday when another problem surfaced in the tunnel between Britain and France at around 10am local time on Sunday.
"Eurotunnel had another infrastructure problem, an electrical incident around 10 am this morning, and so they shut down the two tunnels from 10am till noon," said Eurostar's chief executive Nicolas Petrovic.
The company, which offers passenger rail services between London, Brussels and Paris, had said schedules would return to normal on Sunday. But the electrical incident caused further disruptions, adding to passenger woes after Saturday's fire had forced thousands to rearrange their travel plans.
Passengers affected will be able to either exchange their tickets or get reimbursed, Petrovic said.
Some 400 trains and 1.5 million lorries pass through the tunnel every day. Saturday's fire forced all Eurostar trains already en route to turn back to their stations of origin, while 42 people were evacuated from the truck shuttle using the service tunnel.
Police in England said the fire was "at the French end of the tunnel" and was being dealt with by the French authorities, adding that there were no reported injuries.
Although the incident did not cause major damage, "there was a lot of smoke," said Denis Gaudin, an official from the northern French city of Calais.
The fire sparked travel chaos in Britain and France with long queues for refunds reported at London's St Pancras station. In November 2012, a fire on a freight train halted traffic in the tunnel for two hours.
Four years earlier, a truck fire caused major damage in the tunnel, affecting 650 metres of the structure and halting traffic for 30 hours.
For many passengers on the popular line, the chaos Saturday meant either an enforced stay in France or Britain - or doing things the old fashioned way and going by sea.