Hundreds of people clashed with police in south-west Sydney on Monday night after a prominent Orthodox Christian leader was allegedly stabbed at the altar of his church.

New South Wales premier Chris Minns called for calm after the alleged attack took place while Bishop Mar Mari Emmanuel was saying mass at the Assyrian Christ The Good Shepherd Church in Wakeley just after 7pm.

A live stream of the mass on the church’s website showed a person approaching the altar who then appeared to stab toward the bishop’s head multiple times. Three other people were also injured in the alleged attack.

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The footage of the mass then showed the congregation swarm forward toward Emmanuel before the stream was cut off.

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Police said that they had arrested a 15-year-old at the scene and were forced to hold him at the church for his own safety as a large crowd of several hundred people gathered outside the church.

Riot police were called in to forcibly move the crowd on after police cars were smashed.

A helicopter flew overhead urging the crowd to leave the area.

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“Those violent pictures [from the livestream] are probably what caused the uproar in the community – people saw that, responded and unfortunately we ended up with a public order incident,” NSW acting Assistant Commissioner Andrew Holland told reporters.

He said the 15-year-old suspect, who was held down by parishioners of the church until police arrived, “sustained injuries to his hand as a result of his actions”.

Holland said police were “in the process of taking the teenager from the church” when they realised that a large group had gathered outside and decided to keep the suspect in the church “for his safety”.

Two police officers were taken to hospital after being injured by members of the crowd who broke into “a number of houses to gain weapons to throw at the police”.

Holland said some in the group also threw items at the church in a bid to get access to the suspect.

“They need to let police to do their jobs and let us do the investigation,” he said, promising more arrests over the public order incident.

State premier Chris Minns urged the community to remain calm.

“Disturbing scenes tonight in Wakeley tonight,” he said in a post to X. “My thoughts and prayers are with the victims and first responders who are working to keep us safe.”

“It’s important that the community remain calm and continue to listen and act to the directions of police and emergency services.”

Emmanuel, who gained a large online following during the Covid pandemic, was taken to hospital along with another priest. Both were in a stable condition on Monday night, the church said in a statement posted on social media last night.

“We ask for your prayers at this time. We also kindly ask anyone at the church to leave in peace as our Lord and Saviour, Jesus Christ, teaches us.”

Amid tensions in western Sydney, Inamul Haq Kauser, national president and Grand Imam of the Ahmadiyya Muslim Community, said the community unequivocally condemned the attack “in the strongest possible terms”.

“We extend our deepest sympathy to all those injured in the attack and wish them a speedy and complete recovery.”

The injured people suffered non-life threatening injuries and were treated by NSW ambulance paramedics.

NSW Ambulance said they were called to the church about 7.15pm and sent paramedic teams to the scene.

A spokesman said they had treated a man in his 50s for multiple cuts before taking him to Liverpool hospital.

A man his 30s was also treated for lacerations and taken to hospital.

A man in his 20s was being treated for a cut to his hand and a man in his 60s treated for a laceration to his arm at the scene.

The incident comes with Sydney still reeling from the shocking killings of six people at Bondi Junction Westfield on Saturday.

Australian Associated Press contributed to this report.

• New South Wales
• Australian police and policing