BRUSSELS (AP) — A small blast caused a brief panic at the busy Brussels Midi train station and forced two platforms to close.

Reports said that people started fleeing part of the station after hearing a loud noise Wednesday afternoon. The railway company said police immediately arrived at the scene and closed off part of the building for further checks.

No injuries were reported. It was not immediately known what caused the blast.

Belgium: Authorities mired in almost 200 anti-terror investigations since the beginning of 2017. https://t.co/jHK2cSYgGR — Breitbart London (@BreitbartLondon) August 26, 2017

Part of the rail service was allowed to continue during the evening rush hour.

Police and security services are still a very visible presence in Belgium’s main rail stations following the 2016 bomb attacks at the airport and subway system which killed 32 people.