By Farid Farid

Police are treating a shooting attack at Bondi Beach where 12 people were killed as a terrorist event as they hunt for a possible third gunman but are calling for “calm in the community”.

NSW Premier Chris Minns vowed a swift response from authorities, saying all resources will be at the disposal of police after the hail of bullets was unleashed at dozens of victims at Archer Park at 6.47pm on Sunday.

Twenty nine were injured, including a child and two police officers.

“I can assure the community it (the attack) will be met with a massive, comprehensive and public order response,” he told reporters a mere three hours after the mass shooting.

“We’re sending a clear and unambiguous message to the Jewish community and in fact every Australian that lives in this state that these horrible acts will never be tolerated.”

Police Commissioner Mal Lanyon said he declared the incident a terrorist event at 9.36pm, authorising special police powers for investigation to ensure that any possible third gunman on the loose would be arrested promptly.

“This disgraceful act will not go unpunished,” he said.

He confirmed several investigators were searching homes of suspects in Bonnyrigg in Sydney’s southwest but would not comment on the identity of one gunman killed and another in serious condition in hospital under police guard.

“I cannot confirm there is a third offender but I want to make sure there is no stone left unturned,” he said.

He said there were public order and riot squads deployed throughout the city to ensure there is calm.

“This is not a time for retribution. This a time to allow police to do their duty,” Mr Lanyon warned.

The commissioner also noted a car was found at Campbell Parade at Bondi Beach containing several improvised explosive devices linked to the killed gunman with a bomb disposal unit working on defusing them.

He would not comment on specific numbers of officers positioned but said “as many as is required” from relevant command levels such as counter-terrorism will be assisting in ongoing investigations.

“We have the capability and the resources to investigate this matter … we’re here to keep the community safe,” Mr Lanyon said.