Around 70 people were attending a meeting of the National Democrats and the National Socialist front in the school in Upplands Väsby, in which the groups had hired a room. The firebombs were thrown through a window at about 11 pm.
A small fire started, but those attending the meeting managed to extinguish it.
“They have said that two dark-skinned men ran towards the room and threw firebombs in. A witness has also seen the men,” Sylvia Oldin of Stockholm police said.
Police are treating the attack as attempted arson.