Four police officers in Rio de Janeiro were arrested on Wednesday in connection with the rapes of three women in a favela in the north of the Brazilian city.
Military police inspector general Sidney Camargo said the four men faced prosecution and expulsion after being identified by their alleged victims.
"The military police is outraged and will take all available measures to investigate these crimes; the officers involved will be dismissed" if found guilty, Camargo told the Globo television network.
The four officers were all members of a Police Pacification Unit (UPP), specially created police squads set up to restore law and order in Rio de Janeiro`s crime-ridden slums.
One of the four arrested men in the Jacarezinho favela unit was present during the rapes but did not participate. He is expected to serve as a prosecution witness but remains in police custody with the three others.
The three victims filed a complaint on Tuesday against six police officers and underwent medical exams.
Camargo, who condemned the attacks as "barbaric," said two other police officers had been placed on "administrative" detention.
Rio authorities launched the favela pacification program in 2008 in order to clean up the city`s slums ahead of the World Cup and the 2016 Olympics.
There are currently 9,000 police officers deployed across 253 favelas as part of the pacification program, according to officials.