Members of a task force of the Hong Kong Special Administrative Region's Security Bureau were set to fly to Thailand on Sunday amid signs of a resurgence in cases of Hong Kong residents lured to Southeast Asian countries and detained to engage in illegal work.

Only three of the 120,000 undocumented Thais working in South Korea have registered with the authorities to return home during a grace period continuing through next March, according to Labour Minister Pol General Adul Sangsingkeo.