A fire is raging at a Muslim school in the southern Dutch village of Uden, where the attackers left a message referring to the killing of a filmmaker who was critical of Islam, Dutch television said.
The mayor of Uden told NOS television the fire appeared linked to the murder of Theo van Gogh last week.
NOS said there was a message left saying "Theo rests in peace". Nobody was hurt but NOS showed pictures of firefighters battling flames leaping out of the roof of the building.
Meanwhile the Netherlands today mourned the outspoken filmmaker killed a week ago by a suspected Islamic extremist, while Dutch Muslims rallied to urge reconciliation today after a wave of apparent revenge attacks on mosques.
A 26-year-old Dutch-Moroccan has been charged with the murder a week ago of Van Gogh, whose criticism of Islam enraged Muslims.
The service was broadcast live on national television and was watched on a screen outside the crematorium in Amsterdam by about a thousand members of the public who carried flowers and candles and held placards including one that read: "Never submit to fundamentalism".
"It is time for the silent majority to speak out because the fundamental rules of our society are at stake," Mr Bram Peper, a former mayor of Rotterdam, told the funeral service.
Since van Gogh was shot and stabbed as he cycled to work, a wave of arson attacks has targeted at least eight mosques. A Muslim school in Eindhoven was also badly damaged in a small bomb blast on Monday that police said they suspected was in retaliation for the murder.
Van Gogh's father and sister told the funeral the film director would have deplored the attacks on Muslim buildings.