Police are investigating a serious crash involving an off-road motorbike and a motorised push bike that occurred on Killarney Road, Bridgewater earlier this evening.

Police and emergency services were called to the scene about 7:25pm.

Preliminary investigations indicate the two bikes collided head on.

Both male riders were taken to hospital, a youth sustained minor injuries while a 19 year old male sustained serious injuries.

The road was closed for two hours to allow crash investigators to examine the scene and conduct inquiries. Police would like to thank the local community for their patience and understanding.

Anyone with information or relevant dash cam or CCTV footage, is asked to contact police on 131 444 or Crime Stoppers on 1800 333 000 or at crimestoppers.com.au. Information can be provided anonymously.