A drone was spotted over the camp of World Cup co-hosts Mexico, according to a report, amid fears of team spying.
Broadcaster TUDN published a video on its website showing the flying object in the immediate vicinity of the Centro de Alto Rendimiento in the south of Mexico City.
Coach Javier Aguirre's team are preparing there for their round-of-32 match against Ecuador in the capital on Tuesday.
A drone was also reportedly seen at South Korea training in Mexico earlier in the tournament.
