Police are looking for independent witnesses after a 19-year-old man was assaulted by a stranger near the Westgate Park entrance in Bridlington at around 11am on Monday 13 June.
The 19-year-old was walking with a friend when an unknown man sat with a woman close to the entrance confronted him.
This man allegedly slapped the victim across the face and kept asking the victim and his friend for a fight.
The victim and his friend walked off, followed briefly by the offender.
The victim was not hurt.
The suspect is described as white, aged in his mid 20's and was between 5ft 8ins and 5ft 9ins tall with a slim to average build. He had a thin black moustache and was wearing dark grey/black hooded top with the hood up, grey tracksuit bottoms and black Nike trainers.
Anyone with information about the incident are urged to call 101 quoting log 179 of 13/06/16 or Crimestoppers anonymously on 0800 555 111.