A Serious Crash Investigator was making his way from Hamilton to the scene of the crash and it was likely that the road would remain closed for some time.
"While we're unable to confirm what happened in this crash what we can comment on is that this is the third serious crash in the Waikato today that has left people seriously, and in some cases critically injured.
"This is despite driving conditions today being described as ideal. At this time Police are urging all motorists to make sure they are doing all they can do to ensure they drive to survive this summer."
Earlier today two truck drivers were hospitalised when their vehicles collided near the Mangawhero bridge close to Matamata.
Sergeant Dean Kaio of the Morrinsville police traffic unit said the two trucks had collided on a narrow stretch of road.
"I think at some stage one of the vehicles has gone onto the wrong side of the road," he said.
Details were not immediately known about the third crash.