A man was punched and fell to the ground outside St John's Village cafe.
The alleged assault happened at around 12:25pm on Friday (10 November)
Police say the assailant shouted at the victim before hitting him.
The victim - a man in his forties - suffered facial injuries but did not need medical treatment.
The suspect is described as white, stocky and in his early thirties. He had short blond/brown hair and was wearing dark trousers and left the scene in a white van.
Both men were wearing orange high-visibility jackets.
Any witnesses are asked to call police on 612 612, or contact CrimeStoppers anonymously on 0800. 555 111.
Two Jersey charity leaders become MBEs in King's Birthday Honours
Election voter turnout revealed
States members sworn in as Chief Minister discusses Ministerial options
Man (36) found guilty of child sexual abuse
Healthcare campaigners make a stand as new States is sworn in
Jersey students heading to university to receive Meningitis B vaccine
Farnham to remain Chief Minister
Hole in road causes gridlock in St Helier
