A priest at Montreal's renowned Saint Joseph's Oratory was stabbed in the chest Friday while delivering morning mass, shocking parishioners and those watching a live stream of the service from home.

The suspect was quickly wrestled to the floor by security guards after stabbing Father Claude Grou, rector of the oratory. The priest was taken away by ambulance with minor injuries to his upper body.

"I saw this man coming quickly and taking his knife out and going straight for Père Grou," recounted Adèle Plamondon, who was just finishing the day's reading when the man rose from the pew.

"It was obvious what his intentions were. So, I left screaming to alert the security."

Afterward, she saw the man on the floor being restrained. The attack was captured on a live stream and television broadcast by the Catholic channel Salt + Light.

Father Claude Grou, seen here in an earlier interview, was about to proclaim the gospel to about 60 people gathered in the church when a man stood up from one of the pews, walked behind the altar and stabbed him twice, according to witnesses. (CBC)

She said she spoke to Grou before he was taken to hospital. He was slashed twice and was in shock but seemed to be OK otherwise, Plamondon said.

She said the priest's wounds were superficial because the knife broke.

GRAPHIC WARNING | The following video shows the attack taking place. Please exercise discretion:

Warning: this video contains graphic images. 0:24

Philip Barrett, who was attending the mass along with about 60 people, said the priest was behind the altar, getting ready to proclaim the gospel, when a tall man stood up from one of the pews and started walking forward.

"He walked past the barrier leading into the sanctuary near the altar, and everyone was just initially wondering what was going on, and some people were starting to react a little bit," he said.

"And he walked directly behind the altar and seemed to strike the priest."

Both Plamondon and Barrett described the attacker as a tall, slim man who didn't say anything. Both said they had not seen him at the church before.

WATCH | Parishioner describes what she saw during morning mass at St. Joseph's Oratory:

A witness describes what she saw at morning mass on Friday. Father Claude Grou is in stable condition. 1:02

Priest transported to hospital by ambulance

A spokesperson for the first responder agency Urgences-santé, Benoit Garneau, said Grou was conscious while being transported to hospital.

The injury was to his chest, he said, but he could not say whether there was more than one stab wound.

Montreal police lead the suspect away from Saint Joseph's Oratory Friday morning. (Submitted by Jean-François Lefebvre)

A 911 call was made at 8:40 a.m., and the suspected attacker was already being held by security when police arrived, said Montreal police spokesperson Const. Caroline Chèvrefils.

The man, who is 26, was taken into custody and will be interviewed by investigators later today, she said.

Police say he isn't expected to be charged until Saturday at the earliest.

Oratory spokesperson Céline Barbeau said while she believes current security measures are sufficient, there will be a review in the wake of the attack.

She said there are no plans to start searching visitors or install metal detectors, because it would go against their mission.

'I wish him a speedy recovery,' says mayor

The Montreal archdiocese issued a tweet saying the priest's condition was stable and "all of our prayers are with him."

"We are all shocked by this act of violence that has taken place in our city, in a space dedicated to peace," Christian Lépine, Archbishop of Montreal, said in a statement.

"We know that places of worship of many religions are targets of acts of violence. We must continue to follow the path of peace and love, believing that good will overcome evil through prayer and good works."

In a tweet, Prime Minister Justin Trudeau sent his best wishes to the priest.

"What a horrible attack at Saint Joseph's Oratory in Montreal this morning. Father Claude Grou, Canadians are thinking of you and wishing you a swift recovery."

What a horrible attack at Saint Joseph’s Oratory in Montreal this morning. Father Claude Grou, Canadians are thinking of you and wishing you a swift recovery. —@JustinTrudeau

Montreal Mayor Valérie Plante says this type of attack has no place in the city.

"I am relieved to learn that the life of Father Claude Grou, rector of the [Oratory], is out of danger and that his condition is stable," she tweeted.

"On behalf of all Montrealers, I wish him speedy recovery."

Architecturally, the oratory is the largest church in Canada. Its construction was complete in 1967 on Mount Royal and its dome, one of the largest in the world, can be seen from across Montreal.

Perched on the mountaintop, the oratory was founded by Saint Brother André and is now a pilgrimage site.