UPDATED 11AM: An attempted u-turn gone wrong was the cause of this morning's crash, say police.

Only two vehicles were involved in the incident, which fortunately resulted in no injuries.

When SunLive photographer Bruce Barnard left the scene, one of the vehicles was being towed away, while some traffic management was in place while the scene is cleared.

10.35AM:

A crash on the Kaimai Ranges has caused some traffic delays.

A caller to the SunLive newsroom says traffic heading towards the Waikato was backed up to Belk Road just before 10.30 this morning.

A police spokesperson confirms there was a crash, believed to have involved three vehicles.

She says all cars are now off the road, with only 'a small amount of glass' left behind.

She says there were no injuries.

EARLIER:

A serious crash has occurred on State Highway 29, near the Ruahihi power station.

NZTA reports emergency services are on site.

It is unclear at this stage how many vehicles are involved, or if there are any injuries.

Drivers are advised to travel carefully past the area.

At the scene? Call 0800 SUNLIVE or email newsroom@thesun.co.nz