The 18-year-old was one of two teens treated for knife wounds in Sheffield on Saturday night, with detectives believing that they were both injured in the same incident.
Police officers were at hospital withÂ a 17-year-old boy who had been stabbed in Stannington Road, Stannington, when the 18-year-old arrived for treatment for a serious arm injury.
THEFT: Brother of Sheffield murder victim has '˜last gift' scooter stolen for a second timeÂ The younger was treated for knife wounds to his back and leg but was later discharged from hospital.
He was thenÂ arrested on suspicion of possession of Class A drugs with intent to supply.Â
The older teen remains in hospital this morning while detectives investigate.
Anyone with information should call South Yorkshire Police onÂ 101 and quoteÂ incident 1,093 of October 20Â orÂ Crimestoppers, anonymously, on 0800 555 111. Â