Eurostar services between the UK and Brussels remain suspended as an inquiry into a Belgian commuter train crash which killed at least 18 people gets under way.
Some estimates have put the death toll from Monday's head-on smash at 25, with more than 100 people injured.
The official death count was 18, but efforts to disentangle the two trains are continuing and there are fears more bodies will be found in the wreckage.
The collision, 10 miles south of the Belgian capital during morning rush-hour, happened in icy conditions after a night of light snow fall but the investigation is focused on human error - with the governor of the region, Lodewijk De Witte, suggesting one train had missed a red signal. But the Belgian track operator said officials were keeping an open mind about why two commuter trains on regular runs could have been travelling in opposite directions on the same track.
The force of the impact sent the lead carriages of each train rearing up into the sky, bringing down power lines and derailing a third train. The dead were mostly in the lead carriages of the two trains, with the fate of the two drivers not immediately known. Officials said they were having difficulty identifying some of the victims.
Workman using cutting gear spent hours freeing the injured, and efforts were continuing to disentangle the two trains and restore full power supplies.
The Flanders provincial crisis centre said that alongside 18 known dead, 55 people had been injured. Of those, 30 survivors remained in hospital some in a "very serious" condition.
Eurostar train services between the UK and Brussels were suspended in the immediate aftermath of the crash, with delays between Eurostar stations in the UK and Lille.
A statement from Eurostar read: "Because of the seriousness of the accident and the expected impact on both domestic and international rail services, passengers between the UK and Brussels are strongly advised to postpone or cancel their journeys."
Passengers will be able to exchange or refund tickets, the firm said.