St John Ambulance is calling for compulsory seat belts on New Zealand buses following three serious bus crashes in the past two weeks.
Two people died as a result of the accidents.
St John says all the injuries would have been preventable had passengers been wearing seat belts.
"It's really disappointing for us to attend incidents when we know it's preventable and therefore if those actions had been taken years previously, then there could be people walking about," said Norma Lane, St John director of clinical operations.
The Government has launched an investigation into the safety of buses which St John is keen to participate in.