There were no reports of injuries.
Auckland Deputy Mayor Desley Simpson said the gas main was accidentally struck during kerb removal works, triggering the leak and evacuation.
Emergency services cordoned off part of Khyber Pass Rd in Auckland’s Newmarket after a reported hazardous gas incident.
Fire and Emergency was called at 9.41am, with Remuera and Auckland City appliances attending.
Fire and Emergency told the Herald that a specialist hazardous materials unit from the Auckland station also attended.
Police had advised motorists to avoid the area and expect delays.
Auckland Transport warned that the incident may cause disruptions, cancellations and detours to public transport services.