Australian police arrested seven teenagers accused of following a violent extremist ideology in raids across Sydney on Wednesday to protect the community from a potential attack, officials said.

The seven, aged 15 to 17, were part of a network that included a 16-year-old boy accused of the stabbing of a bishop in a Sydney church on April 15, police said.

Five other teenagers were still being questioned late Wednesday by the Joint Counter-Terrorism Team, which includes federal and state police as well as the Australian Security Intelligence Organisation, the nation's main domestic spy agency, and the New South Wales Crime Commission, which specialises in extremists and organised crime.

More than 400 police officers executed 13 search warrants at properties across southwest Sydney because the suspects were considered an immediate threat, New South Wales Police Deputy Commissioner David Hudson said.

“We will allege that these individuals adhered to a religiously motivated, violent extremist ideology,” Hudson told reporters.

“It was considered that the group ... posed an unacceptable risk and threat to the people of New South Wales, and our current purely investigative strategies could not adequately ensure public safety,” Hudson added.

Australian Federal Police Deputy Commissioner Krissy Barrett said investigators found no evidence of specific targets or timing of an intended “violent act”.

She said the police operation was not linked to Anzac Day on Thursday, a public holiday when Australians remember their war dead.

It has been a potential target of extremists in the past.

A 16-year-old was charged on Friday with committing a terrorist act, a crime that carries a maximum penalty of life in prison, following the knife attack in which an Assyrian Orthodox bishop and priest were injured.

An Australian Federal Court judge on Wednesday extended an order banning social media platform X from showing videos of the bishop being repeatedly stabbed.

Justice Geoffrey Kennett extended the ban, which the court put in place on Monday, until May 10.

X, formerly called Twitter, announced last week it would fight in court Australian orders to take down posts relating to the attack.

Australia's eSafety Commission, which describes itself as the world's first government agency dedicated to keeping people safer online, applied to the court for the temporary global ban.

The teen allegedly spoke in Arabic about the Prophet Muhammad being insulted after he stabbed Bishop Mar Mari Emmanuel and the Rev. Isaac Royel in the Christ the Good Shepherd Church as a service was being streamed online.

ASIO Director-General Mike Burgess confirmed that his organization was involved in Wednesday's operation.

“Australia's security service is always doing its thing to provide security intelligence that enables the police to deal with these problems when we have immediate threats to life or anything else that's evolving,” Burgess said.

He said investigations of children had peaked at 50% of ASIO's “priority counterterrorism case load” a few years ago and the number had since reduced.

But the number of minors under investigation was rising again for reasons including social media content, Burgess said.

“They're a vulnerable cohort,” Burgess said.