Robbers armed with a knife threatened an 18-month-old child as they demanded property from his mother.
Police have released two e-fit images of a man and woman believed to be part of a group of three who approached the victims in Peterborough.
The mother was pushing a buggy along a path between Collingham and Beckingham in Orton Goldhay at about 3.30pm on Tuesday September 5.
Two men and a woman walked up to her. One of the men had a knife and held it towards the little boy in the buggy.
When the mother insisted she did not have anything to give them, they left the scene.
The second man was described as tanned, about 5ft 10in tall, aged between 30 and 14, and a slim build. He was wearing a dark jacket and trousers.
The group also had two young boys with them. One was aged between two and three years old, the second was aged three to five years old.
Click below to hear DI David Taylor from Cambridgeshire