A serious crash involving a motorcycle has closed State Highway 8 near the Tekapo-Pukaki Canal Bridge.

A police spokeswoman said they were notified at around 4.30pm.

The crash occurred near the intersection with Tekapo Canal Road in the Mackenzie District, and serious injuries have been reported.

Emergency services are at the scene.

The New Zealand Transport Agency said a closure of several hours was possible and urged travellers to delay their journeys or find an alternate route.