A gang has forced a 17-year-old girl to drink alcohol and use drugs before raping her in an alleyway.

Five men approached the teenager as she waited for a bus in New Cross, south-east London, at around 8.30pm on 28 October.

She is not from London and had spent the night with friends.

The men took her into an alley off Manor Avenue, where they made her smoke cannabis.

The youngest member of the group asked the others to leave and raped her.

When he was done, a second man indecently assaulted her.

She escaped and fled to a pub on the corner of a pub Upper Brockley Road and Ashby Road, where a woman helped her.

On the way she also knocked on a green front door, which was answered by a man with a baby in his arms.

Detective Constable Sally Leaver urged the man and the woman to contact police. "They are not suspects and I believe they may be able to provide me with important information."

She also appealed for help to identify the suspects.

Police has issued an e-fit of the rapist, described as white, aged 16 to 22, slim and 5ft8in tall. He wore a dark blue tracksuit, had light, spiky hair and said he was Polish.

The second sex attacker, also white, had an Eastern European accent. Detectives said he was in his late 20s, 5ft5in tall, heavily built and with thinning black hair.

The other three, one of which appeared about 40, also sounded like Eastern Europeans.

Before the attack one man's mobile phone rang with a Crazy Frog ring tone.

Anyone with information can call 020 8284 8300.