At least 27 people were injured and another eight were arrested during protests Saturday in Brasilia at the inauguration of soccer's Confederations Cup, police sources said.

Taking part in the demonstration, called by social movements criticizing what they considered the disproportionate outlay of taxpayers' money to organize the FIFA tourney, were some 1,200 protesters who at first expressed their disapproval peacefully.

Despite extreme security measures, the demonstrators managed to reach the gates of Brasilia's National Stadium, scene of the inaugural match between Brazil and Japan, with its strong police cordon and at a time when fans were pouring in to see the game.

Just as the colorful opening ceremony in the stadium began, the protest went from pacific to violent for reasons not very clear but marked by a powerful police charge against the demonstrators.

The cops used tear-gas bombs and were backed by mounted police who rode their horses against the demonstrators, as could be seen on television.

Brasilia's Public Safety Secretariat said that eight people were arrested and that the clashes left 23 protesters and four police injured, though none seriously.

The protest came after a similar one staged Friday by about 500 people who blocked traffic in front of the Brasilia stadium and set fire to some 200 tires.

The protest against the soccer tourney joins demonstrations in other cities around the country against a recent hike in public transport fares, all of which created an unexpected atmosphere of tension leading up to the soccer spectacular. EFE