The knife attack on an ultra-orthodox bishop, and another priest in western Sydney has been declared a "terrorist act". Police Commissioner Karen Webb says she determined the incident was terrorism after reviewing all the information.

A teenager is in police custody over the attack, which injured three others who tried to restrain the assailant. Hundreds of church supporters pelted police with rocks and other projectiles for several hours following the attack, injuring officers and damaging a number of police cars. Faith New South Wales CEO Murray Norman says the events that have unfolded are "shocking" and multi-faith communities are eager to work "arm in arm" with the Police Commissioner and Premier. 

Guest: Murray Norman, Faith New South Wales CEO