The three men who were injured, all volunteers, were hurt while trying to seize the man’s knife, said an administrator at the Centre Culturel Musulman de Châteauguay.
The suspect, a 24-year-old man armed with a knife, was arrested.
Rachid Azmane, an administrator at the Centre Culturel Musulman de Châteauguay, said in a phone interview on Saturday the incident occurred in the basement when people noticed the individual behaving strangely.
The man had changed seats several times and onlookers asked him what he had in his pocket.
“We don’t know what he intended to do,” Azmane said. “A normal person doesn’t come with a knife in their pocket.”
Azmane added the man entered the mosque before prayers and caught the attention of the staff, who noticed he was acting “a little oddly” and became alarmed when they saw he was carrying a knife.
The three men who were injured, all volunteers, were hurt while trying to seize the knife, he said.
Azmane said it seemed clear the suspect, whom no one knew, “was suffering from something.”
On Friday, the Châteauguay police department said the three victims were in their 50s and sustained minor injuries, with one of them taken to hospital for hand injuries.
The suspect was taken to the police station on Friday afternoon, but investigators have not provided any details about a possible motive.
The alleged attacker was scheduled to appear in court on Saturday afternoon.
The mosque reopened its doors on Saturday.