Police want to trace a man in his 20s after a 19-year-old woman was seriously assaulted in Kettering at the weekend.
The incident happened at about 12.30am on Sunday, October 20, in Montagu Street.
The victim was punched, causing her to fall to the ground.
She was taken to Kettering General Hospital with serious head injuries and was later transferred to the John Radcliffe Hospital in Oxford, where she remains in a stable condition.
A 24-year-old man and a 25-year-old woman were arrested in connection with the incident and have been released on police bail pending further inquiries.
Insp Wayne Preece from Northamptonshire Police said: “We are appealing for witnesses to the incident, and particularly we want to trace a man in his 20s, about 5ft 10in to 6ft tall, with fair hair, wearing a red top and dark-coloured trousers.
“There were a number of people who were in the area at the time of the incident, coming out of pubs and clubs, who would have seen the incident.”
He said anyone who had any information should contact police on 101. Information can be given anonymously to Crimestoppers on 0800 555 111.