A gang robbed three men in the street in Brighton in two separate incidents at the weekend.
The first two victims, both aged 21 and from Brighton, were mugged in the early hours of Saturday (11 June).
They were approached by about six men in North Street at about 2.45am as they were walking towards the Old Steine.
One of the men, who showed a knife, demanded that the victims hand over their mobile phones.
The gang then headed off towards the Clock Tower.
A 26-year-old man, also from Brighton, was robbed of his phone and wallet by four men as he walked along Western Road past Churchill Square at about 4am.
The gang headed off towards Dyke Road.
Detective Constable Luke Reynolds said: “The two robberies are being treated as linked.
“Police are conducting inquiries, including viewing CCTV, and are keen to speak to anyone with information about these robberies.
“If you witnessed any suspicious behaviour, please contact police immediately.”
The suspects were described as being of Mediterranean appearance, aged in their early twenties and wearing tracksuits and hooded tops.
Two 19-year-olds, one from Mitcham and the other from Croydon, have been arrested on suspicion of robbery.
The pair were released on bail until Sunday 7 August while officers carry out further inquiries.
Anyone with information is asked to contact Sussex Police on 0845 6070999.