Suspected gunmen held up five shops across Brighton and Hove during a 100-minute spree.
The raids took place last night and today.
The first was at a newsagents in Hangleton Way at 11.03pm and was quickly followed by break-ins to shops in Mill Lane, Portslade (11.19pm), Old London Road, Patcham (11.45pm), West Street, Rottingdean (12.30am), and Sutherland Road (12.40am).
Cigarettes and cash were targeted in each case, although the raiders were not successful at each location.
A silver Mercedes, believed to have been stolen during a burglary in Lucraft Road earlier on Tuesday evening, was used in each raid.
It was found abandoned in Nebitt Road and a helicopter and a dog unit were used.
It is thought that there were four people involved in the raids and enquiries are continuing to locate two others.
A gun was reported to have been seen in two of the incidents.
However it was not found in the car, on the couple arrested or in a search by a firearms dog in the area where they were arrested.
Detective Inspector Clare Shiel said: "This was an incredibly concentrated and focused series of raids and it's quite possible that those involved would have visited the shops in advance.”
A 22-year-old man and a 16-year-old boy from Brighton were arrested on suspicion of burglary non-dwelling and were in custody this morning.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here