Sergeant Craig Madden told the Bay of Plenty Times from the scene that the crash happened at the same spot where a truck carrying LPG cylinders went off the road on Monday.
Madden said the Trustpower TECT Rescue Helicopter had been called as backup.
A local crane driver had stopped to offer help but was turned away.
Katikati ward councillor Peter Mackay, who lives in Turners Rd about 1km from the crash, said he had not heard the emergency services siren and was saddened to hear there had been another serious crash in the area.
"Given the volume of traffic on this road and the shape of the road, it makes it completely unforgiving. If anyone even makes a little mistake the chances of becoming involved in an injury accident are quite high."
Mackay said the NZ Transport Agency had already recognised this stretch as one of the most dangerous stretches of regional highways in the country.
There were 18 deaths, 35 serious injuries and 95 minor injury crashes on State Highway 2 between Tauranga and Katikati between 2012 and 2016. That is the highest death toll of state highways listed by the NZTA as the country's most dangerous.
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This serious crash comes just over a week after the agency announced final options for safety improvements on SH2 from Waihi to Tauranga.
The programme of works includes wide centrelines, side barriers and 26 intersection upgrades delivered between Waihi and Omokoroa from next year, a new 7km highway between Omokoroa and Te Puna and a bypass of Katikati.
NZTA's system design senior manager, Brett Gliddon, earlier said the priority was to prevent people dying or being seriously injured along this stretch of road, and work had already started on interim safety improvements at key intersections.
