The emergency services searched overnight with sniffer dogs for victims of the explosion and fire in central Utrecht on Thursday afternoon but found no-one, leaving the injury toll at four.

The regional safety board said it still cannot completely rule out any deaths in the building on the Visscherssteeg, because the dogs only detect living victims. However, officials said on Thursday that no one has been reported missing.

Fire crews have so far been unable to enter the damaged buildings because it is not safe, safety board spokesman Marcel van Westendorp said. Several properties are “on the verge of collapsing” and need to be shored up before crews can go inside.

Three buildings were badly damaged in the blast and fire. Surrounding properties also sustained significant damage to their windows and roofs while further away the damage is largely limited to broken glass.

Dozens of local residents spent the night with friends or family or in hotels because they were not able to return home.

The cause of the explosion has not yet been established, but a gas leak appears to be the most likely explanation. There are reports that work was being carried out in the building at the time, which the safety board said will be included in the investigation.