Rio de Janeiro police have arrested two suspects over the gang rape of a 16-year-old girl on May 21 after a video of the incident was posted on Twitter. Four other suspects of the gang rape incident are yet to be arrested.

According to the police, it would be difficult to prove the teenager’s allegations that she was attacked by more than 30 men. In the shocking video that surfaced last week on Twitter, the girl could be seen lying naked on a bed in a semi-conscious state while the men could be heard hurling abuses at her and boasting that she was raped by 30 men.

“I am convinced there was a rape, it’s right there in the video, when the guy touched the girl,” quoted lead investigator Cristiana Bento as telling a news conference. “The rape is proven. What I want to do now is verify the extent of this rape and how many people took part.”

The police previously said they were certain that there was a rape but required more evidence.

After the video was posted last week, protests broke out throughout Rio de Janeiro, which will soon be hosting the summer Olympics in August. The highly popular Copacabana Beach became one of the protest grounds, with protesters hanging red-stained clothes along it.

Protesters in Brasilia, who tried to carry out a march to the Supreme Court with flower bouquets and signs that denounced the “culture of rape” in Brazil, were dispersed by the police who used pepper spray on them.

“I fell asleep and woke up in a completely different place, with a man under me, one on top of me and two holding me down, on my hands. Many people laughing at me, and I was drugged, out of it,” she was quoted by the CNN as saying in an interview. “Many people with guns, boys laughing and talking.” She said she is speaking out about this matter and she will wait for “the justice of God.”