Ananova:

German police are hunting a 'prankster' who has been filling footballs with concrete.

The footballs have been left around Berlin with signs saying: "Can you kick it?"

Six of the concrete stuffed footballs have been found so far, all chained to fences.

A spokesman for the Berlin police said: "So far two young men, a 21-year-old and a 23-year-old, have been treated for injuries to their feet after kicking the footballs.

"We think they could have been left by someone who is sick of the World Cup and are investigating the matter as the balls seem to be deliberately designed to injure."