Patrons of a mosque in St-Jean-sur-Richelieu, southeast of Montreal, fear further anti-Islamic attacks after a piece of concrete was thrown through the front window in the middle of the night Sunday.

Worshippers at the mosque say they are shaken by the attack, and worry it could happen again.

'We're scared, we don't know who would do that – we have kids who come here -- what would happen if this happened while they were here – everybody is scared, we don’t know what’s going to happen after,' mosque worshipper Mohamed Moussa told CTV Montreal.

Martin Couture Rouleau, a recent convert to Islam who worshipped at the St. Jean sur Richelieu mosque, was shot and killed by police last month, after running down two Canadian soldiers with his car. Warrant Officer Patrice Vincent was killed in the incident.

Moussa says there is no connection between the mosque and Rouleau’s criminal behaviour, but fears further violence against the Muslim community.

'I feel very bad because we didn't do anything. I come all the time to this mosque -- I’ve been coming for 25 years. We know everybody, they’re nice people. But when this happened, everybody started to be scared,' he said.

Police continue to investigate the mosque attack. Three Quebec City area mosques were also targeted with anti-Islamic messages over the weekend.