An armed robber has met his match in downtown Zagreb when a woman in a money exchange office laughed at his efforts to threaten her, police said.

The masked robber burst into the office and threatened the woman but instead of shrinking with fear she broke out laughing and picked up the telephone to call her boss.

"Knowing that she was protected by bullet-proof glass the employee burst into roaring laughter and called the owner to tell him she was being robbed and that he'd better call the police," a police spokeswoman told the HINA news agency.