Police this afternoon cordoned off an area of Sheffield city centre after an incident near a pub.
Police sealed off the pavement outside the Bankers Draft in Market Place at around 3pm. There was what appeared to be blood on the pavement.
A bystander claimed she had heard someone had been 'slashed' in the incident.
Other witnesses said the incident involved a chase between two men.
A police spokesman said: "Police are investigating after a man, believed to be in his twenties, sustained a facial injury following what is believed to have been an assault in an area close to the front of the Bankers Draft public house and the tram stop in central Sheffield.
"Anyone with information is asked to contact police via: 101 and quoting incident number: 577 of the 27 January."