A three-story apartment building partially collapsed in The Hague today after a fire and explosion, firefighters said, as they searched for people under the rubble.

“Emergency services are rescuing and searching for people and fighting the fire,” the city’s fire department said in a statement.

Rescuers do not know how many people are still under the debris, as well as what may have caused the explosion in this apartment building, which is not far from the city center.

According to local media Regio15, people have already been rescued.

Four people injured in the blast were taken to hospitals, firefighters said.

“The fire is making a lot of smoke. Residents are asked to close windows and doors and turn off air conditioning,” authorities said.

The city’s mayor, Jan van Zaanen, went to the scene to coordinate rescue efforts, according to Regio15.

Floors of the apartment building appear to have been damaged by the explosion, according to Regio15.

The first images broadcast by public broadcaster NOS showed dozens of firefighters battling the blaze and breaking down doors to enter the block of flats.