A gunman waved a gun at terrified staff at Ladbrokes in Market Street, Brighton, this lunchtime and demanded money.
The robber entered the shop at about 12.30pm and made of with cash shortly after. He is described as white, aged late 50s to early 60s, 6ft tall and wearing a dark jacket and woolly hat.
Police would like anyone who saw the incident or who was in or around the shop between 11.45am and 12.30pm to call 0845 6070999 quoting serial 672 of 20/01.