Diversions are expected to be in place following a serious crash on State Highway 29.

Emergency services are at the scene of the crash between a truck and car on State Highway 29, says a police spokersperson.

A caller to the 0800 SUNLIVE news hotline says it's happened near the intersection of SH29 and Old Kaimai Road.

"It looks as though a transporter truck and a car have crashed."

A witness at the scene says there are five police cars, firefighters and St John paramedics at the scene.

Another person who drove past the crash says there was "just a total mess on the road".

Detours are via SH2, SH26 and SH27 or SH36 and SH5.

Motorists are advised to use an alternative route as there will be delays.

SH29 over the Kaimai Ranges is closed.

At the scene?

Call 0800 SUNLIVE or email newsroom@thesun.co.nz