Train workers in southern Belgium are on strike after a crash between two commuter trains in which 18 people were killed.
They say they are protesting at what they describe as deteriorating working conditions, which they say could lead to accidents such as the one at Halle.
There have been suggestions that one of the trains involved in the collision at Halle, south-west of Brussels on Monday morning, may have missed a red light.
The BBC reports the strike is adding to disruption of rail services in Belgium and beyond.
Eurostar trains between Brussels and Britain have been suspended for a second day as a result of the crash.