The tiny and sombre young woman in the red long-sleeved blouse – one of only two she had with her – hung back while her three towering male friends laughed boisterously and talked animatedly outside a restaurant in the border town of Mae Sot, Thailand.

The group of young adults – their ages ranging from 19 to 25 – had reason to be joyful.

A few days before on Feb 3, they were rescued from KK Garden, located on the Myanmar side of the Myanmar-Thai border...