Australian authorities have identified one of the alleged gunmen involved in the deadly Bondi Beach shooting as Naveed Akram, a man from Sydney’s south-west, as investigations continue into the attack that left at least 12 people dead.

A senior law enforcement official, speaking on condition of anonymity, told ABC News that Akram’s residence in Bonnyrigg was raided by police on Sunday evening.

However, authorities said it remains unclear which of the two attackers Akram was, as one gunman was killed at the scene while the other was arrested in critical condition.

The shooting occurred shortly after 6.30pm (local time) on Sunday during the Chanukah by the Sea event, attended by hundreds marking the first night of Hanukkah. New South Wales police said two gunmen opened fire on the crowd, killing at least 12 people and injuring several others.

NSW police commissioner Mal Lanyon said an improvised explosive device was found in a car linked to the deceased attacker. He confirmed that the incident has been designated a

terrorist attack

, though the intended target has not yet been established.

“We have found an improvised explosive device in a car which is linked to the deceased offender,” Lanyon told a news conference.

Lanyon also indicated that one of the shooters was previously known to authorities, but posed no immediate threat. “The person that we know has very, very little knowledge to the police,” he said. “So he's not someone that we would have automatically been looking at at this time.”

Footage aired by the ABC showed two black-clad gunmen firing from a footbridge near the beach. Another video, filmed by a bystander and broadcast on local television, appeared to show a member of the public tackling and disarming one of the attackers.

Eyewitnesses recounted scenes of panic. Lachlan Moran, 32, from Melbourne, told AP: “You heard a few pops, and I freaked out and ran away. ... I started sprinting. I just had that intuition. I sprinted as quickly as I could.”

He said the gunfire continued intermittently for about five minutes. British tourist Timothy Brant-Coles told AFP he saw “two shooters in black with semi-automatic rifles” and several wounded people. Local resident Harry Wilson told the Sydney Morning Herald he saw “at least 10 people on the ground and blood everywhere.”

The Australian security intelligence organisation (ASIO) confirmed that one of the attackers was “known to us, but not in an immediate threat perspective.”

Police and federal agencies continue to examine suspicious items found in the area, with an exclusion zone still in place as Bondi Beach remains largely deserted during the ongoing investigation.