BERLIN (Reuters) - Two masked children pretending to be members of Germany's elite military force triggered a major police operation in the German city of Aachen, police said on Monday.

Neighbors alerted the police after they spotted two "dodgy-looking figures" clad in black balaclavas on a factory site and the police promptly dispatched eight police cars, complete with dogs, to seal off the area.

After surrounding the site, the policemen carefully moved in and ordered the masked suspects to stand still as they were crawling underneath some shrubs and heading toward a fence.

The two boys stopped in their tracks, raised their arms and took off their masks to reveal their identities as one 12-year-old and one 13-year-old boy.

"We've had a series of robberies of scrap metal recently in our area so we were hoping to finally catch the thieves," said police spokesman Paul Kemen.

The police said they were unlikely to press charges and spare the parents any cost.