Five homes on an estate in Arnhem have been destroyed in a fire that took firefighters until late into Sunday evening to get under control. 

The fire broke out shortly before midday but was difficult to put out because of the dense layer of solar panels on the roofs, which prevented water from reaching the blaze. A section of panels was removed on one part of the block to stop the fire from spreading but it was too late to take action at the homes already on fire. 

Some 200 fire officers were drafted in to deal with the blaze and some 16 families had to spend the night elsewhere. Around 100 homes were evacuated when the blaze was at its height because of the dense smoke. 

The cause of the fire has not yet been established. 

The row of eight homes was completely renovated several years ago and fitted with solar panels on both sides of the newly insulated roof rather than tiles. Five of the eight were seriously damaged by the blaze and one has already been demolished. The other three have water and smoke damage. 

Four people who lived in one of the properties have been taken to hospital but as yet the extent of their injuries is unclear. One of them is a pregnant woman who escaped via an upstairs window, the Telegraaf said. 

Arnhem mayor Ahmed Marcouch said that luckily no one had been seriously injured. “Nevertheless, this is a nightmare for everyone concerned,” he told reporters.

Eindhoven University professor Ruud van Herpen, who specialises in fire safety, told broadcaster NOS that the solar panels and the insulation material may have played a role.

“It would appear that there is no separation between the panels and that the cavity wall continues between the different homes,” he said. Cavity walls need to have compartments to prevent fires spreading.

Earlier this month several dozen households were made homeless after a fire in an apartment complex in Amsterdam. That fire broke out in a three-storey roof-top extension added to the former office building five years ago and may have spread via the cavity walls.