Two words teenage boy yelled after allegedly stabbing Sydney bishop at Wakeley, ... trends now

The 16-year-old boy who allegedly stabbed a bishop in an act of terrorism justified his actions by telling witnesses the Christian leader had 'sworn' at one of his prophets and screamed 'Allahu Akbar'  after plunging a knife into his face.

Bishop Mar Mari Emmanuel was attacked while delivering a sermon in the Christ the Good Shepherd Church in Wakeley, in Sydney's west, on Monday night. 

Horrified parishioners leapt into action, with some rushing to the bishop's aid and others helping to detain the teenager inside the church. 

In video of the stabbing, the 16-year-old is heard telling church-goers in Arabic: 'If he didn't swear at my Prophet I wouldn't be here. If he didn't involve himself in my religion I wouldn't be here'. 

In a video circulating on social media, one of the men who helped to hold the teen down tells a female police officer that he 'ran and grabbed him from behind and just pushed him down'.

'He kept saying: 'Allahu Akbar, Allahu Akbar',' he tells the officer.

AFP Commissioner Reece Kershaw was asked to confirm the teenager's religion amid speculation he had recently converted to Islam.

'We have a lot of intelligence to go through and confirm,' he said.

'I can't go through that. One of the things I want to say it's a disgraceful act from the community who attacked police at that scene.'

ASIO boss Mike Burgess was asked if he was aware of the comments and if the bishop had said or done anything to trigger the attack. 

'We're aware of those comments and everything else is open inquiry lines to understand why the individual got to where he did,' he said.