Reports from Belgium say at least 20 people have been killed in a head-on collision between two trains outside the capital, Brussels.
Railway officials said the two trains collided during the morning rush hour at Halle, south-west of Brussels.
The local mayor told Belgian media that at least 20 people had been killed in the crash, but railway officials could not confirm the figure.
Belgian media said the trains collided in snowy conditions.
Mayor Dirk Pieters said "the most recent information we have is that 20 people died".
The trains collided in the commuter town around 0830 local time (0730GMT) Monday.
Railway services in the area, including the high-speed line between Paris and Brussels, have been blocked.
Eurostar said services between Paris and Brussels were cancelled until further notice.
Witnesses described overturned carriages and emergency workers said there was considerable damage to the overhead power lines at the station in Buizingen, the district of Halle where the trains crashed.