Police are investigating two seperate armed robberies in Brisbane’s south side from overnight.

Just after 8.30pm a man armed with a knife entered a convenience store on Gladstone Road and demanded cash from the attendant.

On receiving a sum of cash the man then fled to a waiting red late model Holden utility.

The man is described as wearing black clothing with a balaclava or scarf over his face.

Anyone with information which could assist police with their investigations should contact Crime Stoppers anonymously via 1800 333 000 or crimestoppers.com.au 24hrs a day.

Crime Stoppers is a charitable community volunteer organisation working in partnership with the Queensland Police Service.

A second armed robbery happened at 11.20pm at a service station on Main and Birkdale Roads in Wellington Point.

Preliminary investigations reveal two men entered the store and one of the men, who was armed with a knife, demanded money from the cashier.

On receiving a sum of cash, the pair fled to a waiting vehicle.

The offenders are both described as being of Caucasian appearance, both aged in their 20s, both 180cms. One was wearing a black hoodie short with a white bandana covering his face and white slip on shoes. The other was wearing a white hoodie with vertical stripes and dark coloured pants and a bandana