By Kat Wong and Samantha Lock in Sydney

A mass shooting that killed at least 12 people targeted Sydney’s Jewish community, authorities say, as they describe the incident as a terrorist attack.

One of the offenders has been killed and another is in custody after the gunmen opened fire at Bondi Beach in Sydney about 6.47pm on Sunday.

At least 29 people were injured after hundreds of people had gathered for the Chanukah by the Sea event to celebrate the start of the Hannukah Jewish festival.

NSW Premier Chris Minns said he would send a clear message to the local Jewish community and vowed to take action against the perpetrators.

“This cowardly act of terrifying violence is shocking and painful to see and represents some of our worst fears about terrorism in Sydney,” he told reporters.

“This attack was designed to target Sydney’s Jewish community on the first day of Hanukkah.

“What should have been a night of peace and joy in that community with families and supporters, has been shattered by this horrifying, evil attack.”

A bomb disposal unit has been deployed after a number of improvised explosive devices were found in a vehicle linked to the dead offender.

“A number of suspicious items located in the vicinity are being examined by specialist officers and an exclusion zone is in place,” NSW Police said in a statement at 9pm.

Multiple videos posted to social media show two gunmen standing on a footbridge connecting Campbell Parade to the Bondi Pavilion, firing shots into a crowd.

The men could be seen firing guns as people screamed and sprinted for cover.

A number of people could be seen lying injured and unmoving on grass at North Bondi.

Others were loaded into ambulances on stretchers while onlookers attempted to provide support.

Separate footage showed officers standing guard over a hunting rifle on the ground with an exclusion zone in place.

NSW Police confirmed two people had been taken into custody shortly before 8pm.

Police are advising the public to avoid the scene, but confirmed the shooters had been “neutralised” and there was no ongoing active threat to the public.

People on the ground have reported panic, confusion and disbelief as chaos continued to unfold with emergency services on the scene.

Co-chief of the Executive Council of the Australian Jewry Alex Ryvchin described the incident as “our worst fear realised”.

“It’s a family event, a beautiful event every year,” he told Sky News.

“If this is what we think it is, it is our worst fear realised … if we were targeted it’s something of a scale none of us could ever imagine.”

Unverified footage on social media shows a man running up on one of the gunmen and grabbing his weapon.

The video shows the bystander sneaking up behind the shooter before wrestling the firearm from his grip and pointing it at him.

Daniel, who is visiting Australia from Brazil, said he saw the two shooters on the bridge before about five police cars arrived.

He and a friend hid while the shots were fired and then they ran.

“A lot of people on the sand, on the ground, were trying to scream help,” he told ABC News.

“A lot of people on the floor, kids crying, looking for their mum.”

He said it was hard to believe something like this could happen in Australia.

“After today, I don’t feel safe anymore.”

Prime Minister Anthony Albanese offered his support to the Jewish community.

“We stand with you, we embrace you, and we affirm tonight that you have every right to be proud of who you are and what you believe,” he told reporters.

“There are nights that tear at our nation’s soul.

“In this moment of darkness, we must be each other’s light.”

Israeli President Isaac Herzog called the shooting as a “very cruel attack on Jews”.

“The heart of the entire nation of Israel misses a beat at this very moment, as we pray for the recovery of the wounded, we pray for them and we pray for those who lost their lives,” he said.