Detectives investigating an assault in Sheffield city centre have released CCTV images of people they want to speak to.
Two 18-year-old men were attacked on The Moor at around 3.30am on Friday, November 28 2014
One of the teenagers was taken to hospital with a serious head injury.
He is now recovering at home.
The other man received treatment for an injury to his face.
Officers believe a number of people were present during the assault and have issued CCTV images of people that could hold vital information about what happened.
Anyone who recognises the people in the pictures, or has information about the assault, is asked to contact Snig Hill CID on 101 quoting incident number 98 of November 28 2014.
Alternatively call Crimestoppers anonymously on 0800 555 111.