RNA - Fire crews and police are desperately trying to extinguish the blaze, which has engulfed the entire building.
Police reported that the fire appears to have been started deliberately by an arsonist and it has spread across two buildings, both of which are known to contain asbestos.
The site, formerly a public swimming baths, was bought earlier this year by the Association of Islamic Communities in Culemborg, which had submitted plans to turn the building into a mosque.
There is an existing prayer room at the rear of the building and it is not clear whether anyone was using that at the time of the suspected attack.
It is not clear if anyone has been injured in the blaze or if any arrests have been made.
The fire was said to have spread to two other buildings stocked with heat resistant abstestos.
The building was damaged significantly and part of it collapsed following the blaze.
It is not yet known if someone was inside the building at the time of the fire.
No arrest has been made so far, but the authorities have launched a probe into an alleged hate crime.
The cause of the fire is still unknown and the police are investigating it.
On Wednesday night, five cars went up in flames in the Twerweijde neighbourhood in the city.
The police do not believe that the fire spread from one car to another.
The police are investigating if there is a link between the car fire and the swimming pool fire.
Europe has been victim to various attacks against Muslims.
Earlier in December, a man shot and injured three people when he burst into a Muslim prayer hall in the Swiss city of Zurich.
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