A 17-year-old girl was raped three times in one hour while on a night out in east London, according to police.
Detectives have released images and CCTV footage of two men wanted in connection with the assaults, which took place as the girl made her way home from a night out.
Officers believe that the attacks took place from around 11.55pm on Friday September 29 until around 12:55am, after she became separated from her friends following a visit to a Tower Hamlets night club.
The student was trying to get home to central London at the time she was attacked in quick succession by the rapists, who have been identified by police as suspect 1, suspect 2 and suspect 3. Detectives believe the last attacker was part of a small group.
CCTV footage and still images of two of the men - suspects 2 and 3 - have been retrieved from different cameras that the Met team has used to track the victim's movements around the streets at the time of the attack.
Footage released as part of the appeal can be seen here.
The victim's ordeal started shortly before midnight when she was first picked up on camera being carried by suspect 1 on Cambridge Heath Road. Police said the image quality of the CCTV prior to this first incident is of too poor to release, and the man can only be described as wearing dark clothing.
The pair are then seen appearing to go into a doorway on the same road, after which the man is not seen again on camera, but items of the top half of the girl's clothing were subsequently found by the location.
Shortly after midnight, another CCTV camera picked up the girl stumbling down Mint Street being followed by a different, bearded male, on a racing bicycle - suspect 2.
Police images shows the man was wearing a backwards baseball cap which has a square/rectangular emblem front centre, a hooded zip jacket (open) which is two toned in colour with the shoulders and upper back area being darker, exposing a plain tee-shirt underneath. He was wearing dark trousers and carried a bag on his back.
Officers have established from studying the complete section of this footage that the man on the bike followed the teenager along Mint Street and then as she turned right into Three Colts Lane and headed in the direction of Bethnal Green Overground Station.
When the next camera picked her up a short time later, the man approached her and they reached Corfield Street.
The CCTV indicates that he then directed the victim into an area just back from the street, where they remained for a period of time. The camera then shows suspect 2 leaving this location and walking away. The girl, whose clothing appears dishevelled, is seen emerging shortly afterwards and going further down Corfield Street.
Just minutes later, around 12:4ham, detectives believe that the victim suffered a third attack, this final time possibly involving two or three men. The CCTV captures a third, different man [suspect 3] walking down Cornfield Street and joining two other figures seen in the distance in outline shadow under some trees. In the footage, he appears to bend down towards a spot on the kerb in between some parked cars. Detectives believe it is at this point the victim was sexually assaulted.
This same male is then seen at about 12:55am coming back up Cornfield Street on his own, walking towards the CCTV camera. The clip reveals that the suspect had a distinctive gait, which gave him the appearance of walking unevenly and perhaps being slightly bow-legged.
Following this third attack, a member of the public spotted the teenager lying on the ground in Cornfield Street in a state of distress and immediately rung 999 to alert police. Officers arrived shortly afterwards and took her for examination and specialist support.
Officers from the Child Abuse and Sexual Offences Command (CASO) have already conducted public witness appeals and now are urgently seeking help from any members of the public who can identify either man in the footage or have any other information. They also believe it is possible that she was drugged and are in the process of conducting toxicology tests.
Detective Inspector Suzanne Jordan, from the Met's Child Abuse and Sexual Offences Command, (CAS0) said: "This is a horrific multiple sexual assault on an young female who was simply making her way home after a night out. We would like to thank the members of the public who intervened to help her and possibly prevented her ordeal from continuing even further.
"We believe two of the three were very serious sexual assaults indeed, and are determined to catch the persons responsible for these hideous crimes. I would urge anyone who recognises either male in these images to contact us as a matter of urgency.
"We'd also like to speak to any witnesses who haven't already come forward, or anyone with any information at all however insignificant they believe it might be - it could prove crucial to progressing our enquiries."
Anyone with information should contact the CASO team investigating via the Met on 101 or via twitter at @MetCC.
Information can also be provided anonymously by contacting Crimestoppers on 0800 555 111 or online at www.crimestoppers-uk.org.