It was a night that promised to bring joy and light to Sydney's iconic Bondi Beach as crowds of Jewish families gathered at a park to celebrate the first night of Hanukkah, also known as the festival of light.

They were among thousands of other swimmers, surfers and sunbathers who had flocked to Australia's most famous beach on a scorching summer's afternoon.

But not long after the Hanukkah event kicked off at 17:00 local time and the first free donuts were doled out, festive music was drowned out by the sounds of screams and the echo of gunshots.

It's unclear exactly when the first shot was fired, but the initial call to police was made at 18:47. In the minutes that followed, two gunmen would kill at least 15 people, and injure dozens more, authorities said.

A local high school teacher, Chavi, told the BBC she dropped to the ground to protect her baby as bullets were flying above us.

It was pandemonium and chaos, another attendee, who identified himself as Barry, described as he watched a throng of people trying to escape the scene that had suddenly devolved into a nightmare.

In one verified video, upbeat music from the Hanukkah event can still be heard in the background as people crouch down, and shots are heard, interspersed with shrieks.

As panic spread from the park to the sand, videos show terrified beachgoers sprinting away from the gunfire. Screams, honking car horns, and ambulance sirens filled the air in the next chaotic minutes.

Verified footage provides a timeline of the attack, stating that the gunmen utilized an elevated position to carry out the shooting.

Witnesses reveal the horror as one brave individual tackled one of the gunmen and managed to disarm him, potentially saving lives. However, chaos continued as police arrived and the situation escalated.

Investigations indicate the gunmen's background and prior activities are under scrutiny as the community continues to grieve.