Hundreds of people in Brazil have expressed their outrage at the gang rape of a teenage girl by 30 men after the shocking video of the brutal attack was posted online by bragging attackers, according to "Press TV" , an Iranian news network. The protesters rallied in front of the Legislative Assembly of Rio de Janeiro on Friday, shouting slogans and carrying placards and banners in condemnation of the horrifying crime. The Brazilian police also commenced a thorough investigating into the brutal mass rape of the 16-year-old teenage girl, two days after the attackers posted the shocking video of their crime on social networks. It is suspected that the gang rape occurred on May 21 in the crime-stricken city of Rio de Janeiro, the second most populous municipality in Brazil, which will also be the host to the Olympic Games in August. Police said at least four of the culprits with “direct or indirect” roles in the crime have so far been identified. Meanwhile, Brazil's acting President Michel Temer condemned the assault as a "barbaric crime" in a message on his Twitter account, and vowed to bring the perpetrators to justice. The United Nations women’s rights agency also expressed indignation at the attack. “Apart from the fact that these are young women, these barbaric cases are similar in that the teenagers were lured by their attackers in premeditated plots. They were violently attacked in a context of illegal drug use,” UN Women in Brazil spokeswoman Nadine Gasman said on Thursday.