State Highway 2 is closed due between Paeroa and Waihi due to a serious crash.

A Waka Kotahi spokesperson says the closure is between Normanby Road and Dean Crescent.

"Delay your journey or consider an alternative route," says the Waka Kotahi spokesperson.

For southbound traffic, the spokesperson says a detour is available via "SH2, SH26, SH27, SH24, SH29, Cambridge Rd, Moffat Rd, SH2".

Northbound traffic may do this route in reverse.

A police spokesperson says to expect "significant delays" between Waihi and Paeroa.

"Police were called at around 2.45pm.

"Indications are there have been serious injuries.

"The road is currently closed and diversions are in place."

Enquiries into the circumstances of the crash are underway.