A 24-year-old man was dragged from his car and assaulted in Watford.
The Harrow man was driving an Alfa Romeo in the Alexandra Road area at 10.30pm on Sunday March 23 when he became lost and a car stopped in front of him.
Four men then got out of the silver saloon car and assaulted him before taking two phones.
The victim suffered bruising to his face and sustained a fractured pelvis.
Hertfordshire Constabulary is appealing for witnesses and information.
The driver of the saloon car is described as a man in his late 20s, with light coloured skin and a medium build.
The second suspect is described as a white man, aged around 30 and is slightly muscular. The second suspect is also believed to have been wearing a blue hooded top and tracksuit.
Detective Constable Solomon Beere is investigating and said: "At this stage it is unclear as to the reason why this assault occurred. I would like appeal to anyone who was in the area at the time and saw what happened or perhaps saw the silver car in the area to contact me with information.
"I am particularly keen to hear from a man, who has been described as elderly, who went to the victim after the assault to help. If this was you, please call me."
Anyone with information should contact DC Beere on 01923 47 2984 or via the Herts police non-emergency number 101 quoting crime reference number C4/14/587. Alternatively call Crimestoppers, the independent charity, anonymously on 0800 555 111.