Two men robbed a One Stop store in Purbrook last night and stole cash from the till.
Police said two men wearing dark clothing entered the London Road shop at about 8.30pm.
One of the men jumped over the till area holding a knife, which he used to rip out two till cassettes.
He passed one of the cassettes to the other man, who was holding a crowbar.
The men then left the shop and headed towards Portsdown Hill.
The robbery is being linked to a similar incident at the One Stop shop in Middle Park Way in Havant on Thursday.
A man wearing dark clothing and carrying a knife made threatened a shop worker and stole £500 from the till. He left in the direction of Swaythling Road.
The two men involved in the incident last night were described as about six foot two, with covered faces.
One of the men, who was carrying a knife, was wearing a black hooded top with the top half in camouflage, black trousers with the same camouflage stripe down the side, gloves and tan colour shoes.
The second suspect was carrying a crowbar, and was wearing a black hooded jacket with an emblem on the left arm, black trousers, grey trainers, gloves and a Burberry-style baseball cap underneath his hood.
Detective Sergeant Kathryn Green said: ‘While the men didn’t threaten the staff or use any force during this robbery, this would have been a distressing experience for the workers.
‘We would like the public’s help to identify the men responsible. If you have any information please call police on 101.’