Brazilian police on the hunt for rapists after gang rape was posted on social media

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 a statement the girl gave to the police, she had gone to her boyfriend's house in a poor community in western Rio on Saturday, only to regain consciousness later, surrounded by the men.

She woke up on Sunday, naked and wounded, and made her way home.

It was only days later, the BBC says, that 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.

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.

Campaign groups have been calling for protests over the coming days, the BBC reports.

The United Nations group UN Women issued a statement calling for authorities to investigate the case, but to also respect the victim and not victimise her for a second time by invading her privacy.