Efforts to shut down online scam centers in Myanmar appeared to gain momentum on Monday as a top Chinese security official visited both sides of the Thai-Myanmar border.

Thousands of foreigners freed from online scam-operating centres in Myanmar are stuck in limbo on the border with Thailand after a multinational crackdown on the compounds run by criminal gangs, three sources told Reuters on Monday.

Myanmar has handed over more than 100 Chinese scam centre workers to be repatriated through Thailand, the third batch in a major crackdown on the illegal operations.

China expressed appreciation on Friday for the strong steps taken by Thailand and Myanmar to dismantle scam gangs and protect the life and property of citizens from China and other countries, while pledging to safeguard the safety and well-being of its overseas citizens.

China will fly home about 200 of its nationals found in scam-running compounds on the Thai-Myanmar border, a Thai security official said on Tuesday, as part of a multinational effort to crack down on illegal online operations run from the region.

A sweeping crackdown led by authorities from Thailand, China and Myanmar has dismantled scam centers along the Thai-Myanmar border and freed thousands from nearly 30 countries, but helping them return home remains a big challenge,