German Interior Minister Wolfgang Schaeuble has warned that the possibility of terror attacks with dirty bombs was a realistic threat.

In an interview released Saturday by Welt am Sonntag newspaper, the interior minister said German intelligence agencies had no concrete evidence of any dirty bomb attacks being planned.

But he said it appeared likely to become a terrorist tactic in the future.

"The question is probably no longer if there will be an attack with a dirty bomb, but where and when it will happen," he was quoted as saying.

"We must take this threat very seriously," he added.

Source: Xinhua