He said: "The origin of the riots is the occupation of the building. But that's not really the reason now ... Now other trouble makers have just joined in, taking advantage of the situation."
One person was arrested and the protests turned violent after police evicted youths on Monday who for three weeks had occupied the basement, part of the Islamic centre.
Police guarded the location until Wednesday, and when they left, the youths tried to occupy the building again.
Riots broke out that night, when youths set fires in the area and threw stones and bottles at police.
The city of Malmo has a population of about 270,000, of whom about 21,000 people live in Rosengard.