Emergency services are responding to a serious crash between two trucks on State High 5 near Ohaaki Road.

A police spokesperson says they were alerted to a crash just after 8.30 this morning.

"Initial indications are that one person has been seriously injured, and another three have sustained moderate to minor injuries," says the spokesperson.

The road is closed between Ohaaki Road and Te Toke Road.

"Motorists are asked to avoid the area if possible."