One of the men allegedly responsible for the fatal mass shooting at Sydney's Bondi Beach on Sunday night was previously investigated over ties to a local Islamic State (IS) terrorism cell, local media reported on Monday.

According to the Australian Broadcasting Corporation (ABC), 24-year-old Naveed Akram was in 2019 examined by the Australian Security Intelligence Organization (ASIO) for his close ties to the Sydney-based IS cell.

The ABC reported that both Naveed Akram and his father, 50-year-old Sajid Akram, had pledged allegiance to IS and that an IS flag was found in their vehicle at Bondi Beach following the shooting.

Police in the state of New South Wales (NSW) said on Monday morning that 16 people have been confirmed dead, including Sajid Akram, after the gunmen opened fire on a crowd who had gathered at the iconic beach for an event celebrating the first day of the Jewish festival of Hanukkah.

Another 40 people were being treated in hospital as of Monday, five of whom were in critical condition, and the deceased were believed to range in age from 10 to 87 years old, police said.

Prime Minister Anthony Albanese, who visited Bondi Beach on Monday morning, said that flags would fly at half-mast across Australia on Monday to mourn the shooting.

NSW's Police Commissioner Mal Lanyon said at a press conference on Monday that 328 officers had been deployed to Sydney suburbs with significant Jewish populations.

Officers from NSW Police and the Australian Federal Police were conducting a major operation at Akram's residence in Sydney's southwest suburbs on Monday morning as well as at a short-term rental in the city's west where the two men were staying.

Lanyon on Monday confirmed that the 50-year-old shooter was a licensed firearm holder and had six guns legally in his possession.

The federal government's special envoys to combat antisemitism and Islamophobia, both of whom were appointed to the new roles by Albanese in 2024, on Monday condemned the attack.

Special Envoy to Combat Antisemitism Jillian Segal told ABC radio that government education in Australia has not been sufficient for people to understand how antisemitism "destroys" the Jewish community.

"It's been seeping into society for many years and we have not come out strongly enough against it," she said.

A report released by Segal in July found that antisemitism is ingrained and normalized in Australia and called for a comprehensive long-term response.

Special Envoy to Combat Islamophobia Aftab Malik said in a statement on Monday that there is no justification for the sickening violence or hatred and that the attackers had a clear purpose to spread fear, terror and division within communities.