Brazilian police are hunting more than 30 men suspected of raping a teenage girl in Rio de Janeiro, and of putting video of the attack on social media, according to "BBC". The girl is reported to have gone to her boyfriend's house on Saturday and to have regained consciousness later, surrounded by the men. Arrest warrants have been issued, including one for the boyfriend. The assault has provoked an online campaign against what campaigners call a culture of rape in Brazil. Conflicting versions of the story are still coming in, but the young lady had reportedly gone to her boyfriend's house in a poor community in western Rio over the weekend, where the attack took place. According to a statement she is reported to have given to police, she woke up on Sunday, naked and wounded, and made her way home. Only days later did she find out that some of the alleged rapists had put images of the attack on Twitter. A 40-second-video was widely shared and followed by a wave of misogynous comments, before the users' accounts were suspended. The attack has shocked Brazil, says the BBC's Julia Carneiro. Campaign groups have been calling for protests over the coming days. The United Nations group UN Women issued a statement calling for authorities to investigate the case, but to respect the victim and not victimise her once more by invading her privacy.