Premier Chris Minns confirms that of the 12 individuals killed in the attack, one "offender" has also been killed and another is in custody.

He says the attack was "designed to target Sydney's Jewish community".

What should have been a "night of peace and joy" was "shattered" by a "horrifying, evil attack", he adds.

There were well over 1,000 people in attendance tonight, NSW Police Commissioner Mal Lanyon says, celebrating the Jewish holiday of Hannukah.

The incident has been designated as a terrorist attack by police.

New South Wales Premier Chris Minns begins the conference by saying it's been a "distressing night" in Sydney.

He confirms that two individuals fired towards a crowd - including families - on Bondi Beach.