Officers injured in assaults on police units in Rio favelas

A series of attacks on police posts in Rio de Janeiro's favelas has prompted the State governor to ask for help from Brazilian President Dilma Rousseff.

According to local media, at least three police units were attacked and three officers injured on Thursday in an exchange of gunfire with suspected drug gangs.

The policy to regain control over communities dominated by criminal factions is seen as a key security measure ahead of this year's World Cup.

Iracema Sodre reports.

(CAPTION; Pope Francis visited the neighbourhood during a trip to the city last year)