Dozens evacuated amid Sydney gas fire

They discovered flames inside a roof cavity above six shops on Barrenjoey Road.

About 30 residents from two nearby unit blocks and two people inside the shops were evacuated.

Firefighters were also forced to flee the scene after part of the roof collapsed revealing a ruptured gas line.

A spokesman said the fire had since been brought under control and the evacuated residents had been allowed to return to their homes.

Fire and Rescue NSW is investigating the cause of the blaze.