A father-of-two was punched repeatedly in the face while walking with his family in Salford, Lancs, on the first night of Succot.
The man, aged 22, who has asked not to be identified, was walking with his four-year-old niece and his wife, who was pushing their two children, aged seven months and 16 months, in a pushchair shortly before midnight on October 13.
He was approached by two men who demanded he hand over cash and his mobile phone.
When he told them he did not have anything, he says he was attacked by one of them.
They both fled when a passing car stopped.
PC Neil Jones of Swinton Police said: "This was an outrageous attack on an innocent family.
"Fortunately, the victim only received minor injuries and nothing was taken, but he and his family were absolutely terrified.
"Whoever did this to him is clearly a danger on our streets and must be caught."
The incident is not being treated as a racial attack but the CST's Mark Gardner said: "We have discussed this incident with the local police.
"This was clearly a very distressing attack, even if it appears to have been criminally motivated.
"The attack was reported the following morning to a mobile police unit stationed in the heart of the community during the festivals. This is an excellent police initiative, fully supported by CST and the community."
The attacker is described as being about 17 years old, white, of medium build and unshaven with a flat nose. He was wearing a black padded jacket with a hood and spoke with a local accent.
To date, no one has been arrested.