Brazil has deployed federal troops to Rio de Janeiro in an effort to rid slums of violent crime, drug traffickers, and gangs ahead of the FIFA World Cup in June.

The drug lords are fighting back against the authorities, trying to recapture their territory after years of police occupations.

This violent battle has raised concerns about safety and security at the upcoming World Cup soccer tournament in Brazil, which hundreds of thousands of foreigners are expected to attend.

The final game in the tournament will take place at the Maracaná stadium, a few miles from the Manguinhos slums.

Rio de Janeiro is also hosting the Olympics in 2016.