A gun was pointed at a four-year-old girl during an armed raid on a shop.
The youngster was told by a masked man to look away as his accomplices demanded cash at a convenience store in Wooburn Green, Buckinghamshire on Thursday.
Shop staff and customers were also threatened by the three men armed with a handgun, a knife and a baseball bat.
Police have called it "a terrifying ordeal".
Thames Valley Police are offering a £5,000 reward for any information leading to the conviction of the gang.
Police said one of the men hit a shop assistant over the head
with a baseball bat and then approached the counter at the back of the store where he
attempted to smash through the reinforced window but failed.
The robber then threatened the assistant and forced staff to hand over what
officers have said was "a substantial amount of cash".
Another man demanded money as he threatened staff with a knife.
Escaped from shop
The third member of the gang was carrying a gun and also a baseball bat and
pointed his gun straight at the little girl and ordered her to look away.
The injured shop assistant managed to escape out of the shop through a back
entrance where a fourth robber was waiting in a car.
This man was also wearing a balaclava and carrying a baseball bat.
All four men made off with the cash in a carrier bag in a car which detectives
think was dark green and possibly a Ford Focus or a new-style Fiesta.
Mahesh Patel, 29, manager of the One Stop Convenience Store, where the
incident took place, said he was not there during the robbery but he had seen
what happened on the store's CCTV tapes.
He said: "They were three big guys. They came in with their faces masked and
two of them had baseball bats. They also had a knife and a gun.
"They tried to break the Post Office window and then they put a knife to the
neck of an old lady, a pensioner, who was in the queue.
"Then they pointed the gun at the little girl who was in the queue. She was
about four or five years old. She was shivering and shaking, crying and
"The girl who had the gun at her head knows my staff, and they gave her
chocolates and things afterwards, and called the ambulance and the police."
Detective Constable Sarah Poolman, investigating the incident, said: "This was
a terrifying ordeal for all those people in the shop, particularly the
four-year-old and her mother.
"I would appeal to anyone who was in the area at the time or anyone who knows
about the incident to call police or call Crimestoppers anonymously."