A man was left with facial injuries after being attacked in Birstall Market.
The Batley Neighbourhood Policing Team (NPT) would like to speak to anyone who witnessed the assault in Market Place between 1.40pm and 2.05pm on Saturday.
One of the two men is alleged to have injured the victims ear before both were distracted by a witness.
The first suspect was described as white, 5ft 11ins tall, slim, with ginger short hair that was gelled on top and around 22 years old.
He was wearing dark blue tracksuit bottoms and a dark blue tracksuit top with white near the shoulders.
The second man was white, around 23 years old, 5ft 10 ins tall, stocky and had short brown hair.
He was wearing a high-vis yellow jacket with no top on underneath and had a visible large black tattoo on his chest.
PC Lucy Lindley ,of the Batley NPT, said: “We are investigating this incident which appears to have been a nasty assault on a male by persons unknown to him, leaving him with facial injuries.
“The assault took place at a busy time of day and would most likely have been witnessed. I would ask anyone who has information about this incident to contact myself at the Batley NPT on 101 or Crimestoppers anonymously on 0800 555 111.”