It unfolded over 10 terrifying minutes.

Video has emerged offering a blow-by-blow account of the mass shooting that left at least 16 people dead and dozens injured.

A witness began filming shortly after Naveed Akram, 24, and his 50-year-old father Sajid Akram, had opened fire from a pedestrian bridge at Bondi Beach at about 6.45pm on Sunday.

The footage then followed their movements as the minutes dragged on - until both of them were lying immobilised and the bridge was being swarmed by police and bystanders.

From the camera’s perspective in a building across Campbell Parade, the father and son can be seen working in unison, firing shot after shot into a Jewish Hanukkah gathering in the park at the northern end of the beach.

Leaving one of their rifles discarded on the bridge, they advanced through clouds of gunsmoke, while bystanders who had been using the railings as cover fled for their lives.

After 42 seconds, Akram’s father left the bridge and headed north and out of view - down into the park - while Akram stayed behind and continued using the bridge as a vantage point.

The father was gone for three minutes. While he was in the park, a heroic bystander had tackled and disarmed him.

Meanwhile, Akram kept firing as he moved methodically up and down the bridge. He appeared calm as he rapidly reloaded his rifle, leading to speculation he may have had military training.

Sometimes, Akram could be seen ushering bystanders away - making it clear that he was focused on the Jewish gathering in the park area to the north.

“Where are the cops? Where are the cops, man?” a witness could be heard asking after two minutes.

He then seemed to make an appeal, calling out “Cuz, come on,” to the shooter, who responded by waving him away.

“Come on cuz, bro what are you doing?” the witness continued, but Akram seemed intent on the gathering in the park and kept dismissing his pleas.

Meanwhile, his father returned to the bridge after his hapless detour into the park - re-arming himself with the spare rifle as he rejoined Akram.

Sirens had been wailing since the beginning, but it was after three minutes and 45 seconds that the pair seemed to come under fire from police officers.

They squatted down, cowering behind the bridge railings, but still peeking above their cover and letting off shots.

Sajid Akram was hit from the south and collapsed after four minutes and 32 seconds.

Naveed Akram returned fire to the south, not giving his downed father a second look. Within minutes, Sajid Akram would be dead.

Five minutes had elapsed now - the air was thick with gunsmoke, and Akram was left in a firefight with police.

The man who had been filming the entire rampage from across Campbell Parade seemed to sense that the remaining shooter’s time was limited.

“F***ing die, c***, die!” he screamed.

After five minutes and 49 seconds, Akram appeared to be shot from the north. He collapsed, pulled himself back up, fired off a final shot, and was hit again.

He lay next to his motionless father.

“F*** yeah. Yep, they got him. He’s down, he’s down,” the witness said.

Just under seven minutes after the shooting started, a bystander approached the bridge and appeared to be waving the police over.

Another man, dressed in black, actually walked up to the immobilised shooters and put his hands up. His reasoning for doing this was unclear.

A shot rang out as the police appeared to mistake the bystander for a shooter, but he ducked down and was unharmed.

After seven minutes and 10 seconds, a female police officer hurried onto the bridge with her pistol drawn.

Chaos ensued as the bystander dressed in black got in a scuffle with another man, who seemed to think he had a role in the shooting.

While police officers tried to secure the scene, the bridge was flooded with witnesses who fought among themselves and also landed blows on the shooters as they lay face-down.

One of the bystanders removed his shirt and stomped on the head of one of the shooters before police wrestled him away.

A female police officer later ran onto the Campbell Parade side of the bridge and recovered a rifle from the pavement, taking it away.

This appeared to be a fourth rifle used by the gunmen, which they must have discarded before the footage began.

16 confirmed dead

The death toll from the attack on Monday morning has risen to 16, including a 10-year-old girl and a local Rabbi.

NSW police say the dead range in age from 10 to 87 years.

A further 40 people are injured, including five people in a critical condition. Two injured police officers are in a serious but stable condition.

Naveed Akram, a 24-year-old unemployed bricklayer, is confirmed to be one of the two shooters who opened fire. He is in custody in a critical condition.

The other gunman was his father, 50-year-old fruit shop owner Sajid Akram, who was shot and killed by police. Sajid Akram was a firearms license holder with six guns licensed to him.

NSW Police confirmed on Sunday night they had found explosives in a vehicle on Campbell Parade, near where the shooting took place, which had since been secured and removed. The incident has been designated a terrorist incident.

On Monday morning NSW Police Commissioner Mal Lanyon said there were 328 officers on the ground as part of a counter-terror operation, working closely with the Jewish community and protecting places of worship.

“This is not a time for anyone to be seeking retribution. This is a time to grieve and to heal,” Mr Lanyon said.

Solemn locals were slowly trickling into the beach on Monday morning, leaving flowers and candles in tribute to the victims.

A pram, a toddler’s pair of shoes and a drink bottle were among the debris left in the park, while tables, chairs and large sun umbrellas were scattered across Bondi Pavilion - remnants of the chatoic retreat that thousands of beachgoers had made from the gunmen. At least four cars also stood abandoned in a nearby carpark.