Crowd trouble forced the postponement of Sunday's Uruguayan Clasico between Penarol and Nacional, with fans seen hurling objects at police from the top of the stands.
The Montevideo derby is the fiercest rivalry in Uruguayan football, but passions spilled over as fans clashed with security officials at Estadio Centenario.
Video footage from the open-bowl ground shows Penarol fans dropping missiles, including what appears to be a metal canister, on the police below.
Plastic crates are also seen to rain down on officers behind the Tribuna Amsterdam, with the trouble reported to have started following the arrest of three prominent Penarol fans outside the ground.
"It's one of the saddest evenings in football," said Wilmar Valdez, president of the Uruguayan Football Association. "We have a game with a major police operation and can still not play football."
Asked what action would be taken in the wake of the violence, Valdez added: "It's too soon. It's just happened.
"The relevant bodies will study what they have to study and the interior ministry as well. In the coming days we will see what follows."