NEW DELHI (Thomson Reuters Foundation) - Two teenage girls from rural India, lured by traffickers with promises of marriage and a good life in the city, were rescued from brothels in Delhi at the weekend, a senior police official said on Monday (Jan 18), adding that a search was on for a third girl.

North Delhi's Deputy Commissioner of Police Madhur Verma said the three girls - aged between 16 and 17 - were brought from the eastern state of West Bengal to Delhi, where they were held and repeatedly raped by several men for a month.

"The three youths got in touch with the girls through social networking sites and then through phone calls and convinced them of marriage," Mr Verma told the Thomson Reuters Foundation. "On Dec 13, they took them first to Mumbai where one of the girls was sexually assaulted by two of the youths, and then they were brought to Delhi where they were sold to brothels."

Mr Verma said one of the girls, who was confined to a brothel in north Delhi's Majnu-ka-tilla area, managed to escape on Saturday and was "in a bad condition" on the street when she approached a policeman to whom she recounted her ordeal.

The police raided the brothel and another one in the city's red light district of Garstin Bastion Road, popularly known as G.B. Road, where they found the second girl.

Two women who were running the brothels have been arrested, but the three alleged traffickers named as Raj, Victor and Suraj have fled, with one of them taking the third girl, the police said.

A search is underway to find the suspects and the missing girl, said Mr Verma, adding that charges filed against the two women and three men included rape, abduction and confinement.

"The West Bengal police has been informed and they are travelling to Delhi. They will take the girls, who are currently in a children's home, back to their families," he said.

Almost 36 million people are enslaved worldwide - trafficked into brothels, forced into manual labour, victims of debt bondage or even born into servitude, says the 2014 Global Slavery Index.

Almost half - 16 million - are in India. Many are from poor rural regions and are lured with the promise good jobs or marriage, but end up sold into domestic work, prostitution, or industries such as brick kilns or textile units.

In most cases, they are unpaid or held in debt bondage. Some go missing, with their families unable to trace them.