An autistic teen was attacked from behind on Friday afternoon.
The 14-year-old boy was walking along Nettleham Road towards Outer Circle Road, Lincoln when he was approached by two youths.
He was threatened and then assaulted, he was punched several times and the two offenders ran off.
They wore dark clothing with hoods which hid their faces.
Pc Simon Berger is trying to track down any witnesses to the attack.
He can be contacted via the non-emergency number 101 quoting incident number 339 of December 6.