An estimated £800 was stolen and a window smashed at a Co-op in Bosham early today.
Police received a report of a break-in at the shop in Delling Lane at about 3.30am.
Officers arrived at the scene within minutes to discover the front door wide open and the store full of smoke, activated as a security measure, police said.
It appears a glass panel on the door was smashed to gain entry, before the door was jemmied open, police added.
Once inside, police said the offenders filled large bags with cigarettes from behind the counter. A small safe was also broken into, from which approximately £800 in cash was stolen.
Police said the suspects also forced their way into the warehouse area and accessed a locked cabinet containing personal information, though nothing is believed to have been taken from the cabinet.
The suspects are described as wearing hoodies with the hoods up and their faces covered.
Anyone with any information is asked to contact firstname.lastname@example.org or call 101, quoting serial 152 of 06/09.