No details of the collision (which took place around 8:30am) were released, but all four tracks for east-bound rail services were closed this morning. Police gave permission to open one track around 10:20, and later a second track was opened again.
All this is causing considerable disruption and delays this morning. Some trains followed a different route. The delays have consequences for the whole east-west route up to Bruges and the coast. Rail services between Brussels and Zaventem Airport are not affected.
UPDATE: Fortunately, by Sunday evening rail services via Leuven were back to normal.