Sydney restaurant fire cause unknown

Investigators will soon have access to a restaurant in Sydney's west to determine what caused a fire to break out at the premises.

Ten fire engines with 60 firefighters worked to contain the fire at Irae Buffet Restaurant in Lidcombe after it burst into flames about 2.45pm on Saturday.

By about 6pm, crews had almost extinguished the fire with hotspots still burning in some areas.

Police say it was too early to tell if the fire was suspicious.

No one was injured.

"We are waiting until the fire ground is handed back to us and the building is deemed safe to enter," a police spokeswoman said.

NSW Fire and Rescue Superintendent Greg Rankin said about 60 people left the premises, with those from the Asian food restaurant already exiting the building before crews arrived.

Firefighters tried battling the blaze from within the complex at Bridge Street, but had to step outside once the building showed early signs of collapsing.

Now, the structural integrity of the area is being assessed before investigators enter.

Restaurant manager Richard Kang told AAP the fire started in the packing area before making its way to the ceiling.