"At the moment we're just investigating exactly what's happened," Wright said.
Two rescue helicopters have landed at the crash and a third is on its way. Two fire engines, three ambulances and multiple police officers are at the crash.
The road will be closed for some time and cars are being diverted off SH3 down Ihupuku Rd. Motorists are advised to avoid the area.
A local woman leaving work 500m from the crash described it as "a mess".
She said it looked like a vehicle had crossed the centre line and collided head-on with another vehicle.
The road was wet and slippery, she said.
A staff member at Waverley Four Square said the roads were still slippery after a big frost this morning.
Waverley is in the South Taranaki district, 44km northwest of Whanganui.
Taranaki police this morning warned drivers about ice on the road, after four crashes since 5am.
"We need motorists across Taranaki to be extremely cautious on the roads this morning after four crashes caused by ice on the road since 5am," police said.
"Any patches of road which appear wet will likely be ice and should be treated as such.
"Police are also advising people to check their vehicles and tyres are roadworthy and ensure all windows are completely clear of ice before getting behind the wheel."
Today's crash follows a fatal truck smash in Waverley on Monday.
As of yesterday 187 people had died on New Zealand roads so far this year, up from 183 at the same point in 2017.
Over the past 12 months 382 died, up from 343 in the previous 12 months.
