HALLE, Belgium (AFP) - A head-on collision between two commuter trains outside Brussels during the rush-hour Monday killed at least 18 people and injured some 125, an official said, adding that driver error was suspected. The crash, one of the worst rail accidents in Belgian history, happened at around 8:30 am (0730 GMT), as commuters headed to work in the capital, leaving the front ends of both trains pushed upwards in a mass of twisted metal. Other carriages were hurled on to their sides after the crash in thick snow near Halle, about 15 kilometres southwest of Brussels. Blood-stained wounded were rushed on stretchers towards ambulances along the tracks through falling snow, while an official said doctors were carrying out amputations at the scene. Groggy survivors wandered around in a state of shock or burst into tears as they were taken to a nearby sports centre to be treated. Rescue workers were searching the wreckage for bodies and in the hope of finding survivors hours after the crash, which came after days of snow, while heavy lifting gear was brought in to clear the tracks. Flemish Brabant provincial governor Lodewijk De Witte said the bodies of 15 men and three women had been recovered, but the toll was expected to rise further. Other sources said that up to 25 people had died. Right now there are still bodies trapped in there, a firefighter said. We are also collecting fragments of clothing from the accident site which could help in the identification process, he added. An investigation was under way to determine the cause of the crash, which surviving passengers said came totally without warning. De Witte said one train had apparently failed to stop at a red light. Belgian Prime Minister Yves Leterme expressed his shock, curtailing a trip to the Balkans to head back to Belgium where he was to meet up with King Albert II at the crash scene, his spokesman said. First Liege, and now this, Leterme said, referring to the collapse last month of an apartment bock in the eastern Belgian city where 14 dead were pulled out of the rubble. The shock was terrifying, it knocked us down like ninepins, said one of the passengers, who gave her name as Sylvie as she emerged, with an injured arm, from the crash near the Brussels suburb of Halle. Gaetan, 36, who was in one of the last carriages of the train coming from Mons, near the French border, emerged unharmed. I was lucky. I saw people dead and injured, he told AFP. The crash on a key line caused widespread rail disruption, with all Eurostar high-speed train services to and from London cancelled for the day, as well as Thalys rail services to France, Germany and elsewhere. One of the trains had been travelling northwards from Quievrain, near the French border in the southern region of Wallonia, to Liege. The other was coming from Leuven, in the northern Flanders region. The two trains were carrying some 250-300 people in total, an SNCB rail official said. Messages of aid and condolences also came swiftly from the European Union, which has its headquarters in Brussels. EU Commission chief Jose Manuel Barroso spoke of his deep sadness at the news of the tragedy, and said the EU executive stood ready to help where possible. It was one of the worst rail accidents in Belgian history. In March 2001, two passenger trains crashed head-on at Pecrot to the east of Brussels, killing eight people including both drivers, and injuring 12. That crash was blamed on human error, including that staff at two Belgian stations did not speak a common language.