Brazil announced a security boost of more than 70,000 police personnel for this year’s football World Cup.
In total, 170,000 people are expected to be deployed to guarantee security across the 12 host cities.
President Dilma Rousseff had previously said the armed forces could also be brought in if needed.
Since June 2013, protesters have staged a number of street marches, with some violent episodes, raising concerns about security at the tournament.
Earlier this month, a cameraman died after being hit by fireworks apparently launched by protesters.
In January, the organisers had suggested the tournament’s security personnel would total 100,000 people.
But at a security workshop on Thursday, the organising committee said this figure should be increased.
“We have a lot of concerns, not so much about protests which are a democratic right, but rather about potential violence. We are committed to preventing violence during any protest activity,” a Justice ministry official, Andrei Rodrigues, told reporters.
Around 150,000 personnel will be from the armed services and police.
But an extra 20,000 security stewards will be trained to work inside the 12 stadiums of the tournament, organisers say.
Also on Thursday, Brazil launched its first naval preparatory exercise ahead of the World Cup.