Police have charged a teen with terrorism after he allegedly stabbed a bishop at a church in western Sydney

The charge over the alleged attack on Assyrian church bishop Mar Mari Emmanuel, came as officers zero in on as many as 50 people involved in a violent riot after the incident.

New South Wales Police say counter-terrorism officers interviewed the 16-year-old in hospital yesterday, and charged him with committing a terrorist act.

He was refused bail and a bedside court hearing is expected today.