Sixteen people have been injured after up to 100 bullets were fired during a terrifying public shooting in Sydney’s inner-west.

Police said “rapid-fire gunshots” were fired indiscriminately onto a street — hitting cars, premises and police vehicles — in Croydon Park on Sunday night.

It was initially reported as a rooftop shooting, but new details suggest the bullets were being fired from a window on the second floor of a business and residential building.

Police launched a major operation and ordered people to stay indoors as streets were closed and a lockdown was enforced during the two-hour emergency.

Officers who swarmed the area came under attack and acted with “extreme bravery” to assess the situation.

They reportedly stormed a unit and arrested a 60-year-old man. A high-calibre firearm was seized.

The suspect was apprehended about 9.30pm at the unit above a business on Georges River Road.

“The officers there exhibit extreme levels of bravery in doing what they did,” Acting Superintendent Stephen Parry said.

“They were under rapid-fire gunshots on a number of occasions and they should all be commended for their actions.

Parry said the alleged gunman was “firing indiscriminately at passing vehicles, including police vehicles”.

“There could have been anywhere between 50 and 100 shots that have been discharged,” he said.

He said numerous vehicles and premises were hit and damaged, although a clearer picture would be available in daylight.

Police who arrived on scene were fired upon. Photo: Nine News

Paramedics treated 16 people at the scene for minor injuries. Some were injured by shattered glass as their windows were hit by the bullets, while others were treated for shock.

One 50-year-old man reportedly suffered wounds to his chest and neck.

Police said the victim appeared at Canterbury Hospital with a gunshot wound and was later transported to Royal Prince Alfred Hospital in a serious condition.

No officers were injured, police said.

The suspect was taken to hospital under police guard for injuries sustained during the arrest.

The incident unfolds in Croydon Park, Sydney. Photo: Nine News

Taxi driver Nick told The Daily Telegraph he was driving along Georges River Road when the gunman opened fire on his vehicle.

“As I was driving by I just heard a ‘bang, bang, bang’ on the passenger side of the taxi, and then I looked next to me and I saw a couple of holes in the window and I didn’t even realise there was actually a hole in the roof as well,” he said.

“I smelled the gunpowder, but I assumed because it was grand final night that somebody had thrown firecrackers.

“I pulled up near the corner. But then I thought maybe it’s not safe, because I kept hearing the shooting noises. So I pulled up near McDonald’s and I realised it was real shots.

“I’m just in shock. It feels like it’s a movie. I was just going home to watch the grand final, you know?”

-with AAP