Ten units and a warehouse have been severely damaged in a massive blaze at an industrial complex in Sydney's inner south that was still burning mid-morning on Tuesday.

Firefighters had brought the fire under control by 10am and were working to extinguish hotspots in the complex, which held a range of combustible goods.

Motorists travelling through Beaconsfield and Alexandria have been warned to expect delays due to road and lane closures in the area sparked by the fire on Beaconsfield Street.

At its peak, flames were soaring metres into the air above the fire and nearly 100 firefighters from 25 crews battled to bring it under control.