A truck driver has been rescued after being trapped when his 18-wheeler rolled in the Bay of Plenty early this morning.
The crash occurred on State Highway 2 at Opotiki shortly before 4am, police said.
The driver was initially trapped, but was later freed with shoulder and rib injuries.
Three nearby houses had to be evacuated because the truck had spilled its load of chemicals and liquids across the road, police said.
A Fire Service hazardous material unit was sent to the scene to assess the situation and clear the road.
A diversion was in place via Woodlands, Hukutaia, Crooked and Old Creamery Rds and back onto SH2 via Verral Road.
Motorists were warned to drive with extra care and patience as these were secondary roads with three narrow bridges. Heavy vehicles were advised to avoid the area and to expect delays.
"It is thought that it will take most of the morning to clear the scene, no better estimate can be made until the nature of the load is confirmed," police said at 5am.
Four fire crews in splash suits and the hazardous materials unit from Tauranga were on the scene, Fire Service northern communications shift manager Jaron Phillips said.
Firefighters were wearing protective clothing and breathing apparatus when tackling the spilled chemicals.
Fire Service had a copy of the truck's manifest which listed all the chemicals and liquids on board, and were passing that information to the team on the ground, he said.
An exact figure for the quantity of materials on board was unavailable, but the truck was laden with large pallets of liquids and aerosols at the time of the crash, Mr Phillips said.