RIO DE JANEIRO, May 20 -- A 20,000-strong army of local and federal police officers, and military troops, are set to reinforce security in Rio de Janeiro during the upcoming 2014 FIFA World Cup, local authorities announced Tuesday.

The additional security forces will start patrolling city streets Friday, May 23, well before the World Cup kicks off on June 12, and remain until the end of the month-long tournament. Rio is set to host seven matches, including the final match on July 13.

The beefed up security forces will also have extra patrol cars, helicopters and boats at their disposal.

The decision follows announcements by Brazilian activist groups, such as the Movement of Workers Without Shelter (MTST), to protest massive government spending on such sporting events during the World Cup games.

Authorities said they will be monitoring social networks and websites for news of planned anti-government marches and demonstrations.

Last year Brazil saw the biggest protests in more than 20 years, after officials announced a hike in transit fares as they spent millions in tax payer money on building or renovating stadiums.

Many of those protests, which coincided with the FIFA Confederations Cup games, took place outside stadiums and ended in violent clashes with security forces.

The ensuing police crackdowns, especially in Rio and Sao Paulo, were criticized for their brutality.

In addition to protests, the city is likely to see strikes as well, as it has over the past two weeks. Rio bus drivers have gone on strike twice, public school teachers are currently on strike and the police are planning a 24-hour strike for Wednesday.

The Undersecretary of Security for Major Events, Roberto Alzir, said contingency plans were in place in case strikes occur during the competition.