Altona North Embona Task Force detectives are investigating two armed robberies which occurred at a Werribee shopping centre yesterday.

Police have been told that a man entered a large department store situated on the northern side of the centre around 4.30pm.

As the man entered the store he pulled a bandana up over his face and produced a small hand gun from his pocket.

He approached a female attendant at the cosmetics counter, telling her he would shoot her if she didn’t open the till.

As the attendant was opening the till, the man stepped up behind her and held a pair of scissors at her back, once again threatening her and demanding that she open the till.

The man ran from the store, empty handed, when he saw a co-worker attempting to ring triple zero.

After leaving the shopping centre the robber met up with an accomplice in a small park area in Barber Drive.

At this location the two men attempted to rob a 19-year-old Hoppers Crossing man as he made his way home.

The two robbers assaulted the man and demanded money before, once again, running off empty handed.

The victim received cuts and bruising as a result of the incident.

Police have released still images and CCTV footage in the hope that some one will recognise the man police would like to speak to.