Hundreds of Chilean soccer fans stormed through a security checkpoint at the Estádio Maracanã in Rio de Janeiro, Brazil around an hour before kickoff of their team's big World Cup game against Spain on Wednesday.
The horde of fans, mostly young men, sprinted through the huge FIFA media center underneath the stands, pushing and shoving their way toward a corridor they apparently thought would lead to the grandstands.
Associated Press reporters in the media center said the crowd broke down a temporary wall, sending metal lockers crashing to the ground.
Once inside that corridor, the fans realized it didn't lead to the stands, so they turned around and headed back toward the media room. There, security guards gained control of the situation about 15 minutes after it started, and forced dozens of fans to sit down in a group.
"I was the lone guy standing out there (near entry to press center)," security guard Diego Goncalves told the Associated Press. "All of a sudden they knocked down the fence and just pushed their way through."
Those security guards who did respond were slow to arrive, and there weren't very many of them.
Asked by the AP how many guards should have been watching the entryway where the Chileans busted through, Goncalves said "about 20."
Reuters reported that one female fan was injured and taken outside in a wheelchair.
Many fans covered their face with scarves containing Chile's logo as they were photographed and filmed. Some journalists watching events unfold claimed that the fans had gotten into the stadium without tickets.
FIFA issued a statement on the incident, citing "a group of individuals without tickets [who] violently forced entry into the stadium, breaking fences and overrunning security."
The statement added that "the situation was brought under control quickly and at least 85 intruders were detained according to the military policy of Rio."
As for what FIFA and World Cup organizers will do to prevent further issues at the World Cup, FIFA said it "will communicate further information and measures to be taken in due course."
Here's how reporters on the scene captured the uproar on Twitter, with photos and videos:
This story contains information from the Associated Press and Reuters.