A Catholic priest celebrating morning mass on Friday was stabbed by a man at Montreal’s landmark Saint Joseph’s Oratory.

The mass was being broadcast live on the internet.

Father Claude Grou, who is the church rector, was wounded in the upper body and transported to a hospital, according to the Catholic diocese. He is “slightly injured. We do not fear for his life,” tweeted Jasmin Lemieux-Lefebvre, director of communications for the Catholic Church of Quebec.

Philip Barrett, who was sitting near the front of the church, said he saw a tall white man in his 30s, rise from a pew and quickly walk into the sanctuary to attack Grou.

“He walked over behind the altar and he seemed to strike the priest’s body,” Barrett said. “I think the priest fell down at that time. I do remember the priest was moving away from the man but it happened so quickly there was almost no time to react.”

The suspect was held by the church’s security service and later arrested by Montreal police, said the force.

Saint Joseph’s is in Montreal’s Mount Royal district and Canada’s biggest church.

The mass was broadcast via Salt + Light, “the first Canadian Catholic TV,” which airs the 8:30 a.m. mass at Saint Joseph’s Monday to Saturday.

The last televised mass celebrated by Grou was on March 15:

With files from The Canadian Press