Police are appealing for witnesses after a man was found seriously injured at Lake Macquarie yesterday.

About 9.25am (Sunday 15 May 2016), a 26-year-old man and a male friend were walking along Green Street, Belmont South.

At the intersection of Marriott Street, the man was found lying on the roadway and bleeding profusely from the back of his head. Emergency services were contacted.

NSW Ambulance Paramedics attended and treated the man. The man was taken to John Hunter Hospital where he remains.

Officers from Lake Macquarie Local Area Command attended are appealing for public assistance in piecing together the circumstances surrounding the incident.