Police are stepping up patrols in an area of Newcastle after a number of cars were damaged.
In recent months officers have had a number of reports of incidents where cars have been damaged while parked on Skinnerburn Road, which is popular with people visiting the Metro Radio Arena and the Quayside.
The most recent happened between 2pm and 8pm yesterday, where a Lexus parked on the road had bricks, stones and masonry dropped onto it from the derelict lead works site above.
The debris caused thousands of pounds worth of damage to the car.
Similar incidents have seen items thrown from the site hit moving vehicles driving on Skinnerburn Road, which police say could have caused serious collisions and put lives at risk.
Sergeant Adrian Oakes of Northumbria Police said: "This mindless behaviour will not be tolerated and it is potentially putting peoples' lives at risk.
"Rocks and bricks are being thrown from the site down onto the main road and have hit parked cars as well as moving vehicles.
"It could easily cause a collision and people could end up seriously hurt by this.
"If this is children messing about then it has to stop. We are carrying out regular patrols in the area and will be arresting anyone we find on the site and causing this damage.
"Anyone who sees anybody on the site should report it to police on 101 and we will respond.
"Anyone with any information into this most recent incident is also asked to contact us on 101, quoting reference number 997 16/06/16."