Two commuter trains collided head-on after one ran a stop light at rush-hour in a Brussels suburb, killing at least 12 people and injuring 55, a Belgian official said.
Other officials said the death toll from the crash, which disrupted train services across western Europe, was higher.
The impact peeled away the front of one train car and threw at least one other off the tracks, causing amputations and other severe injuries, witnesses and officials said.
Lodewijk De Witte, the governor of the province of Flemish Brabant, told reporters four hours after the crash that the official death toll was 11, then added later that it had gone up to 12 and “will certainly rise”. He said one train “apparently did not heed a stop light”.
The trains collided in light snow just outside the station at Buizingen at around 8.30am (7.30am Irish Time).
The force of the collision smashed one train deep into the front of the other, tearing back the metal sides. The trains tipped high into the air and broke overhead power lines.
One of the front cars appeared to have careered across the tracks, demolishing a small maintenance shed next to the rail line. A high concrete wall around the train yard seemed to have stopped debris hitting nearby houses.
It was the most serious Belgian train accident since March 28 2001, when eight people died as a crowded train ploughed into an empty train driving on the wrong tracks.
Belgian National Railways spokesman Jochen Goovaerts said his agency was awaiting the outcome of an investigation before discussing the cause of Monday’s accident.
The railway earlier told the VRT radio network that 25 people had died. The suburb’s mayor, Dirk Pieters, told VRT that emergency responders were reporting that 20 people had been killed.
“It was a nightmare,” Christian Wampach, 47, told The Associated Press after medical workers bandaged his head at a sports complex where the less seriously injured were treated.
Those hurt more badly were taken to several hospitals in and near Brussels. The Red Cross appealed for blood donations.
“We were thrown about for about 15 seconds. There were a number of people injured in my car but I think all the dead were in the first car,” said Mr Wampach, who was in the third car of a Brussels-bound train.
Photographs from the scene showed rescuers pulling the wounded from a car that appeared to have tipped on to its side. Other emergency officials rushed victims on stretchers along the tracks.
“When we came out we saw dead bodies lying next to the tracks,” said Patricia Lallemand, 40, who was in the same car as Wampach, and was unhurt.
Wira Leire, 20, said he was woken by a loud crashing sound and leapt to his bedroom window to see two cars jackknifed directly in front of his home.
“There were people lying on the ground next to the train, so I grabbed some blankets and ran into the back garden,” he said. “But I couldn’t climb over the concrete wall, so I just threw the blankets to the rescuers who were already gathering.”
Belgian Prime Minister Yves Leterme cancelled a trip to Kosovo, turning around his plane minutes after landing at Pristina’s main airport, the Kosovo prime minister’s office said.
Eurostar reported on its web site that its high-speed train service in and out of Brussels had been suspended and could remain shut all day.
The international high-speed network Thalys, which links major cities in Belgium, France, Germany and the Netherlands, temporarily halted all services because its trains use the same rails as commuter lines near Hal, said Patricia Baars, a company spokeswoman.
At least four Thalys trains were stopped en route, and the railway operator deployed staff to stations where they were re-routed to provide assistance to travellers on board, she said.
“No (Thalys) train is moving for the moment ... it’s very hard to know today when services will resume,” she said. “It appears this was a very severe accident.”
Thalys has at least 25 round-trip trains operating between Paris and Brussels each day, plus seven linking Brussels and Amsterdam and six from Belgium to Cologne, Germany.