Residents of a Peterborough Avenue unit claim a balaclava-clad man kicked in their back door and shot a bullet into their freezer about 12.30am.

Lake Illawarra police were told the man then fled the unit and was last seen running north towards View Street.

A 15-year-old girl was inside the unit with her mother, brother and mother's partner when the man burst through their back door.

"I was in my bedroom. Mum was cleaning the benches and I heard a smash. I thought she dropped a plate," she said.

"He burst through the screen door. We all ran into mum's bedroom and heard the gunshot."

The bullet, fired from the back of the apartment into the kitchen, grazed a water cooler before lodging in the freezer door.

"It was pretty terrifying. We have no idea what he was after. We don't think he took anything because we haven't noticed anything missing," she said.

A police dog tracked a scent to View Street, where the shooter is believed to have jumped into a car and driven off.

Descriptions of the vehicle are currently unavailable, but the teenager described the man as wearing a green mask and black clothing.

Residents in nearby units said they were considering moving.

Ashley Mullard said she had been woken up by a "massive bang" as the gun went off, and she feared the shot had come from her own stairwell.

"I was asleep, I had no idea what was going on," she said.

"I'm very worried. I was terrified, trembling."

Ms Mullard said she feared for the safety of her daughters, aged three and five.

"I'm ready to move away. I didn't sleep last night," she said.

About midday, another man waited outside the apartment block for a handyman.

He said the morning's events had spurred him to install stronger security doors on his daughter's unit inside the complex.

"She's worried. Of course she is - who wouldn't be?" he said.

Lake Illawarra police are continuing to investigate the shooting.

Anyone with information should contact police on 4232 5599 or Crime Stoppers on 1800 333 000.