At least four people were wounded, including a bishop with a global online following, in a knife attack during a service at a church in a suburb of Sydney on Monday, police and witnesses said, triggering clashes between angry residents and police.

Police authorities said they arrested a 15-year-old male at the scene and were forced to hold him at the church in Wakeley, a suburb about 30 kilometers (18 miles) west of downtown Sydney, for his own safety after a crowd gathered outside and demanded the attacker be brought out.

It was the second major stabbing attack in just three days after six people were killed in a knife attack at a beachside mall in the Bondi area.

Bishop Mar Mari Emmanuel of the Assyrian 'Christ The Good Shepherd Church' was speaking during an evening service on Monday, April 16, when a man walked towards him and lunged with a knife, according to video of the event captured from a livestream on the church's social media page.

Authorities disclosed no motive for the attack and have not identified the suspect.

Two witnesses told Reuters the crowd threw rocks at police. More than 100 police officers were ultimately called in to deal with the unrest, and two were taken to hospital with injuries, police said. Reuters saw two men pepper sprayed.

"There was so much anger because the bishop is loved by them, he’s loved by myself as well, he preaches about the Lord and we love the Lord,” said a local resident who gave her name as Canny.

The perpetrator was taken to an undisclosed location.

The New South Wales ambulance service said four people had been injured in the attack. In a Facebook post, the church said Bishop Emmanuel and a priest, Father Isaac Royel, were among those hurt. Police said no injuries were life-threatening.

"We ask for your prayers at this time. It is the Bishop's and Father's wishes that you also pray for the perpetrator," the church's post said.

Emmanuel was ordained a priest in 2009 and then a bishop in 2011, according to the church's website. The bishop has become a popular figure on social media, with clips of his sermons racking up hundreds of thousands of views on platforms including YouTube.