MELBOURNE, Australia: Five teenagers accused of following a violent extremist ideology have been charged with a range of offenses in an investigation that began with the stabbing of a bishop in a Sydney church, police said on Thursday.

The five were among seven boys arrested across southwestern Sydney on Wednesday in a major operation by the Joint Counter-Terrorism Team. The team includes federal and state police, as well as the Australian Security Intelligence Organization and the New South Wales Crime Commission, which specializes in extremists and organized crime.

Two 16-year-olds and a 17-year-old have been charged with conspiring to engage in or planning a terrorist act, a police statement said. The older boy was also charged with carrying a knife in public.

The remaining two, ages 14 and 17, were charged with possessing or controlling violent extremist material accessed online.

All five remained in police custody.

Two other boys arrested on Wednesday had not been charged so far, police said. Three other juveniles and two men were being questioned by police but were not arrested.

More than 400 police officers executed 13 search warrants on Wednesday at properties across southwestern Sydney and one in Goulburn, a city about 200 kilometers (120 miles) south of the eastern Australian city.

New South Wales Police Deputy Commissioner David Hudson said on Wednesday that the arrested boys "adhered to a religiously motivated, violent extremist ideology."

Police claimed that the network included the 16-year-old boy accused of stabbing Assyrian Orthodox bishop Mar Mari Emmanuel and Rev. Isaac Royel during a church service that was being livestreamed on April 15. That boy was charged last Friday with committing a terrorist act, which carries a maximum penalty of life in prison.

The two clerics survived the attack, which was the second high-profile recent stabbing to rock Sydney. Three days earlier, a 40-year-old man with a history of mental illness and no apparent motive was shot dead by police inside a shopping mall after he killed five women and a Pakistani security guard, and wounded a dozen others.