Three robbers threatened staff and customers at a bookmakers before making off with cash.
The men, all wearing balaclavas, one brandishing a hammer and another a crowbar, went into Coral, in High Street, Histon, at just after 8pm on Saturday (December 14).
Two of them jumped over the counter and demanded a safe was opened.
The trio left with a substantial amount of cash and made off in a car.
No one was hurt but members of staff were upset and shaken up by what happened.
Two members of staff and two customers were there at the time.
Det Sgt Russ Toovey, who is investigating, said: “This was a terrifying incident for staff and customers in the bookmakers and I am determined to catch the men responsible.
“I am keen to speak to anyone who saw a vehicle with a loud exhaust leaving the front of the premises at about 8.10pm.
“Anyone with any information should not hesitate to get in touch.”
Anyone with information should contact Det Sgt Toovey on 101 or Crimestoppers, anonymously, on 0800 555111.
For all the latest news see Thursday’s (December 19) Echo.