The Department of Conservation is asking for help over the killing of a flock of protected birds in Bay of Plenty

DoC says 21 red-billed gulls were killed when a vehicle drove through their colony on Pukehina Beach on July 26.

Security footage shows a dark four-wheel-drive being driven at Dotterel Point about 12.20am.

DoC believe the driver killed the birds - and is likely familiar with the area.