Thames Valley Police is appealing for witnesses following an assault in Olney.
The incident happened today (14/14) between 1.20am and 1.45am in the High Street.
A 50-year-old man sustained serious injuries after it is believed he was assaulted whilst walking along the High Street near the junction with Spring Lane.
He suffered a significant head injury and was taken to hospital for treatment, where he remains at this time.
A 24-year-old man from Olney has been arrested in connection with this incident and is currently in police custody.
Investigating officer Detective Inspector Tracey Benham, based at Milton Keynes police station, said: “This incident left a man seriously injured and in need of hospital treatment.
“We believe that a number of people were present at the time of the offence, and we would like to speak to them to establish exactly what happened prior to the victim sustaining his injuries.
“If you can help, call 101, quoting reference number 43240170123, Alternatively, you can make a report online or call Crimestoppers anonymously on 0800 555 111.”