St John says two of its ambulance officers have suffered a "horrific ordeal" after being assaulted while tending to a patient at City Medical Centre in Napier.
On Friday about 11.15pm an officer was in the back of an ambulance treating a patient when a man allegedly entered the vehicle and became aggressive.
St John territory manager Brendon Hutchinson said when the second ambulance officer returned the pair together managed to get the man out of the vehicle.
"The assailant then entered the front of the ambulance, smashing the front windscreen and hurling equipment at the ambulance officers," he said.
"The ambulance officers were shoved and bruised (one sustaining minor injuries) but they managed to drive away and alert Ambulance Communications and Police to the situation."