Sydney supermarket firebombed in fourth attack

The hunt is on for arsonists who firebombed a supermarket in Sydney's south-west forcing dozens of people to evacuate.

It's the fourth time the shop has been targeted and the investigation has now been handed over to the state crime command who are looking for any links to organised crime.

The Mount Pritchard supermarket was set alight again about 3am today, just one week from its grand re-opening.

READ MORE: Protesters clash with police in Melbourne CBD

"I looked out my window and I could see smoke and I'm just like not again not again," witness Christine Zybrands said.

Fire sparked in the back storage area with emergency crews forced to cut through the roller doors to get in.

"There were 25 evacuations in total but some of those were just from surrounding properties," Tim Hassiotis from NSW Fire and Rescue said.

Authorities are investigating the blaze, which destroyed everything in the back storeroom.

READ MORE: Families rattled after teens allegedly broke into their homes to steal cars

"It's looking for any traces of ignitable liquids that may have been used," Hassiotis said.

The supermarket was first attacked on the April 26. Then, just 11 days later there was another attack.

That time a ute rammed through the front and the shop was set on fire. 

There was an almost identical hit on the June 6, but it was a car through the front and the damage bill was up to $500,000.

On June 13, two men were arrested and charged but it still happened again.

Bollards were installed after the last attack to try and stop any more cars from ramming through the roller door.

But it didn't stop any further attacks, as this time the culprits went round the back.

DOWNLOAD THE 9NEWS APP: Stay across all the latest in breaking news, sport, politics and the weather via our news app and get notifications sent straight to your smartphone. Available on the Apple App Store and Google Play.