A man with learning difficulties was ‘verbally abused, chased and punched’ on Sunday, say police.
The force is appealing for witnesses to the incident which took place at about 6pm, on Sunday.
A spokesman said the 26-year-old victim was walking along Lumley Road towards the Clock Tower.
They said: “He was approached by four male teenagers who verbally abused him, chased him and punched him.
“The victim has learning difficulties and this assault is being treated as a hate crime.”
Anyone with informaction should call Lincolnshire Police non-emergency number 101, quoting incident 310 of January 17.