5.30pm update: A motorist who arrived at the scene of the house bus crash in Mangorewa Kaharoa Gorge on Sunday afternoon, says it's unbelievable that anyone could have survived.

Police say that they received a report of a crash on SH36/Pyes Pa Rd, Ngawaro at 1.52pm.

"The house bus appeared to have suffered brake failure coming down a steep hill," says a motorist at the scene.

"It went straight ahead on a right hand corner, hit the bank at about 70 km per hour, launched about five metres into some trees and then straight down 20 metres and came to rest right way up at the bottom on the edge of a creek.

"One guy was thrown clear, the other crawled his way backwards and climbed out through the crushed roof.

"Both were injured but didn't appear to be too bad," says the motorist.

"[It's] absolutely unbelievable anyone could have survived, let alone both."

The historic horse trough in the Mangorewa Kaharoa Gorge. Photo: File.

Update, 2.30pm: Emergency services are at the scene of a house bus crash in the Mangorewa Kaharoa Gorge on State Highway 36 between Tauranga and Rotorua.

The Tauranga Transport Operations Centre report that two people have been injured, one with serious injuries and the other with moderate injuries.

One lane is reported to be closed on SH36.

"The road is likely to be closed for some time and diversions are being put in place at Te Matai Road, Dudley Road, and Whataroa Road," says a Police spokesperson.

Motorists are cautioned to expect delays, and consider delaying travel or use alternative routes.

Earlier, 2pm: A bus has crashed in the Mangorewa Kaharoa gorge on State Highway 36 between Tauranga and Rotorua near Te Matai Rd.

The Tauranga Transport Operations Centre report that there have been injuries, with people ejected from the bus.

Emergency services are en route to the scene of the crash.

Police say that they received a report of a crash on Pyes Pa Rd, Ngawaro at 1.52pm.

"We are not at the scene yet, so have no further details at this time," says a Police spokesperson.

Motorists are advised to expect delays, to delay travel or use alternative routes.

An update will be provided as soon as more information is available.

At the scene? Phone 0800 SUNLIVE or email [email protected]