Copa Libertadores final celebrations marred by violence in Buenos Aires

Two police officers were injured and at least 20 people arrested in Buenos Aires in the early hours of Monday as River Plate fans celebrated winning the Copa Libertadores.

Approximately 20,000 fans gathered at the Obelisk monument in Argentina's capital city on Sunday to celebrate their team's fourth Copa Libertadores title after beating rivals Boca Juniors.

After a 2-2 draw in the first leg at La Bombonera, River prevailed 3-1 after extra time in Madrid.

Back in Argentina, La Nacion newspaper reported that a violent and inebriated group of people caused damage to shops, attacked bystanders and threw objects at police, forcing officers to use tear gas and rubber bullets to disperse the crowds.

Violent acts by hooligans, including the attack of Boca's team bus which left some fans and players injured, had been the reason why the game that was originally scheduled for Nov. 24 at River's Monumental stadium was moved out of Argentina by CONMEBOL.

In stark contrast, things ran smoothly in Madrid where unprecedented security measures were in place, with thousands of officers on duty for the game at the Santiago Bernabeu.

"Thank you to the more than 2,000 police offers as with your professionalism you have made it possible for us to enjoy the Copa Libertadores final between Boca and River," Spain's interior minister, Fernando Grande-Marlaska, tweeted.

Grande-Marlaska told Onda Cero radio: "We have an exceptional police force that has more than risen to the occasion."

Argentina president Mauricio Macri, a Boca supporter, may not have been happy with the result of the game but was delighted with the behaviour of the fans that travelled to Spain to watch the game.

He sent out several tweets praising fans of both clubs for showing their maturity in ensuring the game went ahead this time around without complications.

"I want to congratulate the River and Boca fans that shared in a peaceful manner this historic game at the Bernabeu stadium," he said. "The exemplary behaviour of the thousands of Argentinians that travelled to Madrid proves that the problem of our football is not our fans but a bunch of delinquents that use mafia violence to defend their businesses.

"With a thrilling spectacle that we will remember for a long time, today we ascertained that football is a party that can be experienced in peace.

"Congratulations to River and all of their fans for their triumph in this historic game. We of Boca know that football always gives you an opportunity for a rematch."