That is the message from NSW Police and the Australian Defence Force for members of the public thinking of entering restricted Defence spaces in Port Stephens and the wider Hunter.

The warning comes after a number of trespassers in 4WDs, quad and trail bikes have in recent months been detected entering the Salt Ash Air Weapons Range.

"These trails are restricted for a reason - they are in close proximity to locations with live weapons training and aircraft operations," Group Captain Peter Cluff, senior ADF officer at RAAF Base Williamtown, said.

"It is irresponsible for people to not only be trespassing, but damaging property along the way. We are working closely with NSW Police to educate the public that these routes are not a shortcut and are extremely dangerous."

Police and ADF said "numerous" people had been observed entering restricted access trails at the Salt Ash Air Weapons Range, located about 6km to the north-east of the Williamtown RAAF Base.

Cars, quad bikes, trail bikes and motorcycles have all been sighted on the tracks within the range, which borders the Port Stephens townships of Medowie, Oyster Cove and Salt Ash.

The air weapons range is a restricted area. Authorisation is required to enter the grounds, including all roadways and other immediately adjacent operating areas.

Port Stephens-Hunter Police District Chief Inspector Alan Janson said entering a restricted area without authorisation is "dangerous, reckless and illegal".

"The RAAF base here at Williamtown undertakes some high-risk training exercises, with several areas identified as 'no-go' zones for the public. This includes certain tracks and trails within the air weapons range," he said.

"It's come to our attention that some locals are driving and riding through this area, putting their safety at risk by trespassing at restricted locations.

"While we note some people may not be aware they are accessing out-of-bounds areas, these tracks are also clearly marked and blocked - with others actively damaging property or breaking through gates to access the trails.

"We will continue to work with the ADF here at Williamtown, conducting joint operations to detect illegal activity and will pursue legal action if it is deemed necessary."

RAAF Base Williamtown has a number of active vehicle barriers in place at entry points to the Salt Ash site.

Any person wishing to access the site must report to access control and provide valid ID.

It is not the first time Port Stephens police and Defence has teamed up to enforce laws around restricted spaces. In December, police, Defence, Newcastle Airport and Port Stephens Council launched a signage campaign to educate the public about the rules and responsibilities that come with owning a drone.

The campaign was prompted following incidents of drones being flown within the Newcastle Airport and Williamtown RAAF Base air space, which is illegal.

Anyone with information about trespassers or anything that may assist police is urged to contact Crime Stoppers on 1800 333 000 or use the online reporting portal nsw.crimestoppers.com.au.