Protesters at the G20 summit in Argentina

As world leaders met in Argentina's capital, tens of thousands of demonstrators marched in the city — surrounded by tight security.

A 12-square-kilometre area where the summit is being held was cordoned off by police.

In total 25,000 officers are deployed to the city in case of any violence.

But with protesters kept well away from the leaders, the demonstrations generally had a party atmosphere.