Beth and Molly Fight
A snapshot of the BBM footage of the alleged assault.

Police in Cardiff are on the hunt for a teenage girl who is shown being violently assaulted in an "horrendous" viral video.

Officers investigating the attack, which is believed to taken place in a bathroom, are keen to get in contact with the unidentified victim who is shown being beaten unconscious in the footage, the Mirror reports.

In the 52-second clip, distributed on BlackBerry Messenger, the pyjama-clad girl is punched, kicked, stamped on and has her head smashed against the bath. After she passes out, her attacker pours detergent on her.

The suspect is described as having dark hair tied in a bun, false eyelashes and black-and-white patterned ankle boots.

A parent in Cardiff raised the alarm with the local force after coming across the video, entitled "Beth and Molly Fight", on her child's mobile phone.

Det Insp Shane Ahmed of South Wales Police said: "In the video, this girl is being absolutely beaten in a bath.

"She is repeatedly punched, kicked, her neck is stamped on, her head is hit against the bath.

"The attack appears to continue after she falls unconscious, with bathroom detergents poured over her."

He continued: "It is a horrendous, prolonged attack and it is made even more worrying by the fact that we don't know who the victim is, where the attack has taken place, or even if she is alive and breathing now.

"We can tell from the labels on the products in the bathroom that this appears to have taken place somewhere in the UK, and we have contacted other forces to make them aware.

"Our priority is to identify the victim and ensure her welfare."

Detectives have teamed up with police forces across the UK in a bid to trace the victim and her suspected attacker.

Anyone with information is asked to urgently contact Cardiff CID on 029 2052 7420 or Crimestoppers anonymously on 0800 555 111.