Police are appealing for information following an incident that occurred on Park Terrace in Thornaby shortly after 3am today, Wednesday 1st January 2014.
An 18 year old man was found in the street with a head injury and was taken to hospital.
He is being treated for his injuries, which are not believed to be life threatening at this time.
Two local men aged 22 and 26 have been arrested on suspicion of assault in connection with the incident.
Police are particularly keen to trace anyone who was in the Oxford Street or Park Terrace area of Thornaby and who may have seen a disturbance around the time of the incident.
Enquiries are ongoing and anyone with information is asked to contact police on the non-emergency number 101.