A knifeman threatened members of staff at a Tesco store - one person required hospital treatment.
Police are appealing for witnesses to an armed robbery at Tesco Express Stores, in Freshwater Square, Eastbourne, on Sunday.
Two men entered the premises just after 6am and threatened members of staff with a knife before stealing £400 in cash and a quantity of cigarettes. One staff member was slightly injured and received medical treatment.
The suspects are being described as white, aged in their late 20s to early 30s and wearing dark clothing and scarves.
Detective Sergeant Jo Benton said: "We are keen to hear from anyone who may have seen these men in the area or have any information to assist the investigation."
Call Sussex Police on 101.