A Christian bishop and multiple churchgoers have been stabbed by a man during a televised service in western Sydney. 

Police confirmed an operation was under way in Wakeley in the city’s west on Monday night following reports of a stabbing. 

A video circulating on social media shows a man dressed in black approaching a man named as Mar Mari Emmanuel, the bishop at Christ the Good Shepherd.

He is seen stabbing the man multiple times to the head and upper body at the altar as parishioners screamed and ran to his aid. 

NSW Police said there were reports a number of people had been stabbed.

“Officers arrested a male and he is assisting police with inquiries,” police said in a statement.

Those injured suffered non-life threatening injuries and were being treated by paramedics.

WARNING: GRAPHIC VIOLENT CONTENT BELOW