Last year, Deutsche Bahn said it suffered property damage worth 7.6 million euros ($10 million) from people spray-painting its carriages. Now the railway operator has said it will test a new method of surveillance to curb the vandalism.

Drone-like aerial vehicles will be equipped with four helicopter-style rotors and be able to shoot high-resolution thermal images of train depots at night - when the majority of vandalism is thought to take place.

Deutsche Bahn said it would only use the drones over its own property, not in public areas, which is in line with German anti-surveillance laws.

The unmanned aircraft, which do not compare to the high-tech drones used in the military, are remotely steered by a "pilot" at heights of up to 150 meters (500 feet) and swift speeds of up to 54 kilometers (33 miles) per hour.

An operator will evaluate the images, which the company plans to use as evidence, and alert security personnel if mischief is afoot.

hc/rc (AFP, dpa)