A bullet has been fired at the equestrian press centre in Rio, narrowly missing a New Zealand official.
The bullet, which landed near the area where athletes speak to reporters, was identified as a 5.56m assault rifle round.
Nobody was harmed after the bullet pierced the plastic surface of the tent, which sits in the northern suburb of Deodoro.
Press reports suggest that Kiwi chief Diana Dobson narrowly avoided being hit, in what is a further headache for Rio security forces.
The opening day of the Games had already been overshadowed by a controlled explosion carried out on a suspect package near the finishing line of the men's road race.