"It started with one woman called Shahinoor who escaped from her captors in Syria. She called her mother who complained to us," Commander Khadaker Golam Sarowar of RAB-3 told the Thomson Reuters Foundation on Monday.

"Shahinoor was supposed to go to Lebanon. Instead she was taken to Dubai with five other women, and then on to Syria where she was sold to different people -- sometimes to work as a maid, sometimes for sex. She told us there were others."

Sarowar said the 34-year-old woman was "extremely sick and unable to move." Bangladeshi officials in Syria flew her to Dhaka where she is being treated for a kidney illness, he added.