A man was attacked on a bus in Rotherham by a stranger who then assaulted him again when he got off.
The 33-year-old victim was using the number 2 service from Maltby to Rotherham at around 3.40pm on Tuesday, May 24 when he was attacked on the top deck.
When he got off in Wellgate his attacker struck again.
A South Yorkshire Police spokeswoman said: "The victim suffered bruising and swelling to his head, causing him to briefly lose consciousness.
"The unknown man is reported to have been wearing a red top.
"Were you on the bus that afternoon? Did you witness the incident?"
Call South Yorkshire Police on 101, quoting incident 709 of May 24.