SYDNEY, Dec 15 (Reuters) - Two alleged gunmen who killed 15 people at a Jewish celebration at Sydney's Bondi Beach were a father and son, police said on Monday, as Australia began mourning victims of its worst gun violence in almost 30 years.

A bystander seen in a widely circulated video disarming a gunman during a deadly shooting rampage at a popular Australian beach is being heralded as a hero who saved lives.

An investigation is underway after a deadly attack on a Hanukkah event at Bondi Beach in Sydney, Australia, on Sunday.

An event to mark the first day of Hanukkah was taking place at Bondi Beach when the shooting took place, killing at least 15 people ages 10 to 87. Officials declared the shooting a terrorist event and said it was “designed to target” Jewish people.

Israeli Prime Minister Benjamin Netanyahu on Sunday sharply criticised Australian Prime Minister Anthony Albanese following a deadly shooting at a Jewish holiday event in Sydney, linking the attack to Canberra’s support for Palestinian statehood.

Israeli President Isaac Herzog and Foreign Minister Gideon Saar blamed Australia's government for a deadly attack on a Hanukkah event that killed 11 people.

Officials in Australia said father and son attackers killed at least 15 people in a shooting during a Jewish holiday celebration in Sydney. Video showed a bystander tackling one of the suspects. NBC News’ Raf Sanchez has more.

The assumption of safety under which Australians operated, that public spaces were assuredly gun-free, has been shattered.