Police are investigating a fire at a Port Noarlunga business in the early hours of this morning.

About 3.50am today (Wednesday 22 June), police and fire crews were called to a restaurant on Saltfleet Street after reports that a Molotov cocktail had been thrown at the front door.

Fleet Street Social (cocktail bar and restaurant), have since posted on Facebook that they are closed until further notice.

A flare had also been used to try and start a fire.

The flames were extinguished by MFS crews before any major damage could occur.

Anyone who may have witnessed suspicious activity in the area is asked to call Crime Stoppers on 1800 333 000, or online at www.crimestopperssa.com.au