Two bookmakers have been held up at gunpoint in an East Sussex town in less than 24 hours.
Sussex Police said a man robbed Ladbrokes in Gildredge Road, Eastbourne, at 0840 BST on Monday.
On Sunday, at 2250 BST, a man wearing a false brown moustache attempted to rob Betfreds in Cornfield Road.
In that incident, a member of staff ran into a back room and locked the door and the raider left the bookmakers empty handed.
Police said two other betting shops have been targeted in Brighton and Hove in the past ten days.
Det Insp Paul Phelps, of Sussex Police, said: "We are obviously very concerned that this is the second armed robbery in 24 hours."
He said the investigation was "in the early stages" and it was not yet clear if the four incidents are linked.