The attack on Saturday that left six people dead and a knife assault on a bishop on Monday labelled terrorism by police, have inflamed social media and public discourse and led to calls for calm.

"Switch it off if you can. Switch it off," Environment Minister Tanya Plibersek said on ABC News on Wednesday.

"I really don't think that the social media companies are doing as much as they ought to be to support the police in their efforts to keep calm in the community," she said.

E-Safety Commissioner Julie Inman Grant told ABC Radio she would consider legal options against X and Meta, the parent company of Facebook, after issuing removal notices for extreme material on Tuesday.

The companies have 24 hours to act.

"I wouldn't say that they don't care," Grant said, adding "unfortunately, we have seen a ratcheting back of trust and safety operations across the platforms and across the industry."

Asked by a listener whether she had the power to shut down X in Australia, Grant said she had a wide range of powers including "different kinds of court notices", which she would consider at 2.30pm on Wednesday once the 24-hour window had expired.

A 16-year-old boy has been arrested over what investigators labelled a religiously motivated terror attack on Monday at Christ the Good Shepherd Church at Wakeley in the city's west.

Bishop Mar Mari Emmanuel and a priest were hospitalised along with the boy.

Videos and photos of the attack, captured during a live-stream of the sermon, started being posted to X, formerly Twitter, sparking a riot outside the church.

The dramatic events at the church came two days after a 40-year-old man attacked shoppers, mostly women, in the Westfield Bondi Junction centre.

He was shot dead by police.

Prime Minister Anthony Albanese and NSW Premier Chris Minns have both raised concerns about the role of social media in spreading false information and sowing disunity.

Australian Associated Press