St John wants harsher penalties for assaults against first responders - after a weekend of attacks and threats towards staff - and damage to ambulances

Crews were forced to lock themselves in vehicles to avoid aggressive behaviour, and one case involved a sharp weapon.

District Operations Manager Andy Everiss say no one was hurt, but it can have an emotional and psychological impact.

Meanwhile, Police are still looking for whoever slashed the tyres of three ambulances at South Auckland's Manukau Station on Saturday.

St John says the damage was discovered at the point of dispatch, delaying an emergency response.