Police found a garage still in flames when they arrived Monday afternoon in the town of Hennef, east of Bonn, following reports of an explosion. The owner, who claimed he bought the munitions at a flea market, has been arrested and a major security operation is now underway at the scene, Deutsche Welle reports.
"At around 3.20 p.m. several residents rang the emergency line and reported that there had been several detonations in a garage," a police spokesman said, according to the Telegraph.
Authorities evacuated several homes, cleared an area near the scene and shut down a major piece of highway and railway as a precaution in case there were any more explosions.
One neighbor who heard the explosion told German language newspaper Bild, "It was banging and it didn’t stop banging."
The paper also said that the collector regularly searches for old weapons in nearby fields using a metal detector, as unexploded bombs from World War II are found frequently in the country.
The owner, 51, reportedly lives with his parents and was taken into detention and now faces charges stemming from weapon law violations. While police are still investigating the incident, all remaining explosives were detonated in a field.
In early May, 50,000 people had to be evacuated from their homes in Hanover so three WWII-era British bombs could be defused, the second largest evacuation of its kind carried out in the country’s history.