One lane has reopened after a truck fire blocked State Highway 29 on the Kaimai Range.

Police were called to the fire at the Kaimai summit about 11.05am.

No one was injured.

A Fire and Emergency NZ spokeswoman said two trucks were called to the scene and left after extinguishing the fire.

Waka Kotahi NZ Transport Agency said there was stop/go traffic management in place and asked that drivers allow extra time.

Earlier, it advised that both lanes were closed.