Amsterdam’s Islamic secondary school, the Cornelis Haga Lyceum, was the target of an attempted arson attack the night before pupils returned after the holidays, according to school leaders.

Director Soner Atasoy told NRC that vandals appeared to have thrown a brick through a classroom window and poured flammable liquid over the teacher’s chair. A canister of accelerant fluid was found in the playground.

The school has been the focus of controversy last year over its teaching methods, with education minister Arie Slob attempting to cut its funding for allegedly failing to teach pupils the values of democracy and the rule of law.

Police in Amsterdam said they were treating the incident as high priority. ‘Our forensic experts are at the scene gathering evidence,’ said a spokesman.

The school had defied Slob’s orders to replace its board of directors in the wake of a highly critical report by education inspectors. The Council of State ruled in November that the minister was breaking his ministry’s own rules by attempting to cut off the funding summarily rather than at the end of a six-month winding-down process.

Atasoy said he was unsurprised that his school had been targeted by vandals. ‘We have been constantly painted in a bad light by the council in Amsterdam and the ministry of education. There comes a point when it’s no longer a question of whether, but when it will happen.’

Amsterdam’s mayor, Femke Halsema, froze funding for the school earlier in the year after the security service AIVD told her it was being funded by ‘undemocratic groups’. But the inspectors’ report found no evidence to support allegations that pupils were being subjected to Salafist teaching.