Police in Rio de Janeiro are investigating the case of a policeman who appears to have fired a live round at anti-World Cup protesters, a scene caught on an Associated Press video.
Rio state's military police say the officer presented himself to headquarters Monday.
He is being questioned and has been taken off duty pending the investigation. It is not clear if any protesters were hurt by the shot he allegedly fired.
Meanwhile, Rio's civil police confirm that one of their officers was caught on camera brandishing a gun in a separate incident during the Sunday night protests. He later fired two shots in the air.
The action unfolded during a small but violent anti-World Cup protest that happened near the Maracana soccer stadium just before Argentina defeated Bosnia-Herzegovina.