A Hato Hone St John spokeswoman said it was notified of an incident in Limeworks Rd, in Milburn, at 1.56pm yesterday.
Two patients were treated and transported to Dunedin Hospital — one in a serious condition and the other in a moderate condition.
Other patients were assessed but did not require hospital transportation.
They responded with one ambulance, an operations manager, a first response unit and a rapid response unit, the spokeswoman said.
A police spokeswoman said the road was blocked for a period of time while emergency services were at the scene.
Police were making inquiries into the circumstances of the crash, the spokeswoman said.