A three-story apartment block in The Hague partially collapsed Saturday after a fire and explosion, firefighters said, with first responders searching for people under the rubble.

Axar.az reports that citing AFP, four people have already been pulled out of the debris and taken to hospital, as elite teams with sniffer dogs deployed to rescue others trapped by the disaster.

It was not known how many people were still missing nor what caused the explosion in the block of flats not far from the center of the city.

“We still don’t know how many people might be under the rubble,” a police officer on-site told.