Women and children make up the majority of the more than 600,000 Rohingya Muslims who have fled violence in Myanmar for neighbouring Bangladesh, many escaping with only the clothes on their back and desperate to survive any way they can.
Confined to congested tent cities near the border without any prospect of work, refugees are willing to take whatever comes their way -- and many have fallen prey to traffickers, according to the International Organization for Migration (IOM).
Young girls in particular are at high risk, with the IOM documenting cases of refugees being lured with promises of marriage or jobs in big cities that end instead in forced labour or sex work.
"In one case, a number of adolescent girls, who were promised work as domestic helpers in Cox's Bazar and Chittagong, were forced into prostitution," the IOM said in a statement this week.
Kulthum lost her husband in the ethnic violence that tore through Myanmar's Rakhine state this year.
Separated from her parents and children during the journey to Bangladesh, she was approached by a man after arriving in Kutupalong, a gigantic camp housing hundreds of thousands of refugees.
His marriage proposal offered a brighter future away from the squalor of the camp and a chance to lay her unhappy memories to rest.
But the couple were never married.
Instead Kulthum -- not her real name -- said she was taken to a brothel, where she was dosed with methamphetamine and forced to have sex with up to seven men a day.
She later learned the man who promised to marry her had been paid 8,000 taka ($100) to deliver her there.
"I became scared, but didn't have the least idea what was in store for me," she told AFP in the border district of Cox's Bazar.
"I was sold to become a prostitute," she said, weeping at the memory of the ordeal.
Police crackdown
Human trafficking networks have expanded as the refugee population has climbed and are now "rife" throughout the camps, the IOM said.
Bangladesh has deployed its top police unit, the Rapid Action Battalion, to Cox's Bazar to crack down on traffickers, many of whom manage to evade detection despite restrictions on non-authorised personnel entering the refugee camps.
"The traffickers are not sitting idle. They are targeting women and children, especially those coming alone," the battalion's chief in Cox's Bazar, Major Ruhul Amin, told AFP.
Traffickers also attempt to separate refugees from their families during the chaos that accompanies their arrival in Bangladesh, Amin said.
A checkpoint in the coastal town of Teknaf set up a month ago has already rescued 30 women and children from the clutches of traffickers, he added.
Another security official, who asked to remain anonymous, said there had been cases of criminal syndicates organising fake passports for Rohingya women who are then sent abroad, especially to Malaysia and the Middle East.
The IOM said it was also aware of cases of Rohingya refugees being trafficked overseas.
Falling prey
Dhaka has prohibited the Rohingya from leaving the camps, fearing an influx in its bigger cities, and has set up checkpoints along the roads leading to the tented settlements.
More than 20,000 Rohingya have been turned back but aid workers say that unless the refugees are taught about the dangers of trafficking, they will keep trying to leave the camps in search of a better life.
Local charity worker Mohammad Hossain Shikder runs workshops in the camps to educate refugees about the tactics employed by people smugglers.
"They will always come up with a lucrative and believable offer, like a job in a garment factory or marriage to a well-off person," Shikder told a group of 20 young men and women in Kutupalong.
"Sometimes, parents are convinced by upfront payments of 40,000 taka or more. They are sold dreams that a woman can even make 500,000 taka, which is an impossible amount."
For many of the stateless refugees stuck inside the camps, the prospect of earning a living is enough to lure them into the trap laid down by traffickers.
Months after she was sold into prostitution, Kulthum managed to escape from the brothel, but found herself back in Kutupalong, penniless and alone.
Eventually she returned to the sex trade and now lives in a seedy hotel room in Cox's Bazar.
"One day I hope to find my children and parents again. I am saving money for them," she said.
