Hundreds of people are putting themselves in danger each week by four-wheel-driving, surfcasting and biking inside a restricted air weapons range.
Now the New Zealand Defence Force is using drones to track down trespassers and get them to leave.
The Kaipara Air Weapons Range is an area of sand dunes, beachfront, wetland and tussock used for Defence Force training activities and weapons testing, including bomb drops.
Public access is banned all year round, even when there is no military activity. But plenty of people still access the area, especially in summer, according to an NZDF spokeswoman.
The range is at the northwest end of South Head on the Kaipara Harbour, north of Auckland. It extends down the west coast as far as the "26 Mile" warning sign and includes part of the south coast of the Kaipara Harbour entrance.
Twenty banning notices were issued during one compliance check last week, and many members of the public were turned back before they encroached on the range, the spokeswoman said.
Police, fisheries and NZDF personnel spoke to more than 200 people during the session, carrying out fisheries education and inspections, traffic and vehicle infringement tickets, and a number of warnings against trespassing.
Defence Force protection patrols are taking pictures of unauthorised people and vehicles within the zone to improve security, before chasing down the culprits and issuing them with a warning.
Specialist infra-red cameras are also deployed at strategic locations around the NZDF zone to capture vehicle movements.
The peak pressure on range security is in the next few months, especially on weekends and holidays, as more people access the beach.
Many beach users are from the wider Auckland region and are unaware that access to the range is banned all year, the spokeswoman said.
"There is an incorrect perception by some members of the public that access is possible when the range is not active – this is simply not the case."
The range is clearly defined on the seven NZDF warning signs located at strategic points in the South Head area, and these signs also outline the ban on access at all times.
"There are always new people in the area and regionally who do not understand the 24/7 restrictions on access to this area. Some others knowingly ignore the rules, putting themselves and others in danger," she said.
Banning notices are issued by NZDF patrols and the NZ Police have the jurisdiction to prosecute repeat offenders identified during patrol operations on the range.
The range is managed from RNZAF Base Auckland in consultation with Ngati Whatua o Kaipara (via Ngā Maunga Whakahii o Kaipara Ngahere Ltd), Hancocks Forestry, the police, and the Department of Conservation.