Suspected arsonists set an Islamic elementary school on fire in the latest in a string of arson attacks in the Netherlands in the wake of the killing of a Dutch filmmaker, allegedly by an Islamist extremist.

Firefighters were struggling on Tuesday night to put out the fire at the burning Bedir school in the southern town of Uden, where someone had scrawled "Theo rest in peace" in the building in homage to slain filmmaker Theo van Gogh.

Uden Mayor Joke Kersten told Dutch television that she didn't know the exact cause of the fire but suspected arson. She said the school had not been the target of prior attacks.

Arsonists attempted to burn down two Protestant churches overnight, in Utrecht and Amersfoort, in apparent retaliation for the bombing of a Muslim elementary school in Eindhoven on Monday, police said.

Muslim sites have been the target of a half-dozen attacks in the past week. No injuries have been reported in any of the attacks, and no arrests have been made.

In Utrecht, police arrived to find that a church window had been smashed and a container of flammable liquid thrown inside. In Amersfoot, several Molotov cocktails were thrown at the outside wall of a church.

Tensions have been high in the Netherlands in the week since the murder of Van Gogh, who was shot and stabbed in Amsterdam by an alleged Islamic radical for making a movie critical of Islam.

On Tuesday, hundreds of mourners attended the funeral of controversial Dutch director Theo van Gogh, killed by a suspected Islamic radical in an attack that has shocked traditionally tolerant Dutch society and fuelled ethnic tensions.

Only about 150 people -- relatives and close friends of the deceased -- were allowed inside the crematorium building while outside some 700 people watched the proceedings outside giant screens.