A charity shop worker was threatened with a knife before thieves stole cash from the British Heart Foundation shop in Bletchley.
The incident happened just after 6pm on Saturday when two men went into the shop in Queensway just as the victim was closing for the night. One of the men threatened her with the knife before the two ran off with a quantitiy of cash.
The first man is Asian, 5ft 10ins, in his early 20s, and slim wearing dark trousers, a black quilted jacket, gloves and a face covering.
The second man was also in his 20s, 5ft 7ins, wearing black baggy trousers, red trainers and a grey hooded top. He was also wearing gloves.
The men ran towards Brooklands Road in the direction of Water Eaton.
Detective Inspector Dave Dachtler, from Milton Keynes police station, said: “I am appealing for anyone with information about this incident to contact police.
“This offence is abhorrent particularly because it was an incident in which the offenders targeted a charity shop. Many people who work in establishments such as these give up their time for free as volunteers for good causes.
“It appears the victim thought the offenders were making a charitable donation, but when she approached the men, they threatened her with violence.”
“Fortunately in this case the victim was not hurt, but was left very shaken by the incident.”
Any witnesses can call police on 101 or Crimestoppers, anonymously, on 0800 555 111.