A huge blast and fire broke out in the central Dutch city of Utrecht on Thursday, with several buildings collapsing and at least four people injured, according to officials.
"After the explosion, several buildings collapsed. Four people were injured. They were taken to the emergency hospital," the local emergency services department said in a statement.
It was not immediately clear what caused the blast nor whether there were more victims.
Officials called on the local population to stay away from the area, as emergency services rushed to the scene.
"The fire department is currently investigating how the collapsed and damaged buildings can be safely searched to determine if anyone is still inside," authorities said.
"Extensive damage is reported in the surrounding area."
TV images showed a plume of smoke rising above the historical city centre and rubble strewn across the streets.
"It's also possible that there are still people under the rubble," city mayor Sharon Dijksma told public broadcaster NOS.
"I knew right away that this was bad," NOS quoted one witness, Margot Schroevers, as saying.
"The ground was shaking," she said.
The local hospital in Utrecht has set up an emergency trauma centre. The Red Cross urged volunteers to head there as soon as possible.
