Belgian authorities stopped a bus heading to Brussels from northern France on Thursday morning and arrested three people after a passenger overheard them discussing a possible “terrorist” attack, prosecutors said.

Belgian police stopped the bus after a passenger heard talk of a possible terrorist attackPhoto: Belga / ddp USA / Profimedia

“Every time we receive a message like this, we take it very seriously and don’t want to take any chances,” a spokesman for the Ghent prosecutor’s office told Reuters, adding that police were currently checking the bus, the 46 passengers and their luggage.

The representative of the prosecutor’s office refused to reveal any details about the suspects, as well as the content of their conversation.

Belgium is on high alert after Islamic State claimed responsibility for an attack that killed two people in Brussels in October.