Undocumented workers in Myanmar-Thailand exploited post-floods.

Burmese migrants caught in Thai floods. Photo: Peter Biro/The International Rescue CommitteeWhile the Burmese government has re-opened a key border checkpoint between Thailand and Myanmar to accommodate thousands of migrants fleeing Thailand's flooded factories, undocumented - and now unemployed - migrants face extortion and abuse as they try to return home, according to migrants and activists.

Aye Than, a 35-year-old Burmese employee, was working in one of Thailand's hardest-hit provinces, Ayutthaya, in a furniture factory until it flooded.

"I've lost everything in the flood, but I cannot leave because I have no money to feed my family in Myanmar," said Aye Than.

Thousands of Burmese migrants have been fleeing flooded industrial parks in the provinces of Ayutthaya, Nakhon Sawan, Nakhon Pathom and Pathum Thani, according to migrant workers' groups.

As quoted in local media, the Federation of Thai Industries estimates losses from the seven hardest-hit industrial estates could reach US$13 billion, covering 891 factories and 460,000 workers.

"Many people want to stay and get their unpaid wages back, but some simply gave up because they were traumatized and have lost all contacts with their employers," said a representative from the Thailand-based Migrant Working Group NGO coalition.

Aye Than said since his work permit expired in October, police have arrested him several times, with immigration officers on both sides of the border demanding up to $80 each time as a condition of his release. He is now earning $4 per day doing odd jobs. "It is impossible for me to pay the fees," he said.

Risking arrest

Without cash, identity documents or social connections, migrant workers are among the most vulnerable groups in the ongoing floods, said Claudia Natali, labour migration programme coordinator at the International Organization for Migration (IOM) office in Bangkok.

"Irregular [undocumented] migrants who have no passport or work permit risk being arrested, but also those with a work permit or ID risk arrest and deportation when they leave the provinces where they are registered."

Under Thai law, migrant workers - except domestic, fisheries and water transport workers - are forbidden to travel outside their registered provinces.

But as an emergency relief measure during one of the country's worst natural disasters in recent history, the government has ordered the police not to arrest migrants fleeing floods, said Jackie Pollock, director of the MAP Foundation, a Chiang Mai-based NGO working with Burmese migrants in Thailand.

However, immigration services are still pursuing undocumented migrants, said Pollock.

Meanwhile, illicit brokers are charging migrants unreasonable transport fees to take them to the Myanmar border, said Andy Hall, a consultant with the Thailand-based Human Rights and Development Foundation.

Many of these trips are at night, said Hall. "This is very dangerous and makes them even more vulnerable to the extortion by immigration officers [in Thailand and Myanmar] and militia groups [in Myanmar]."

More than one million legally registered Burmese migrants work in Thailand, making up to 80 percent of the country's total migrant population and 5 percent of Thailand's labour force, according to IOM.

While the number of undocumented migrants in Thailand is unknown, IOM estimated there were 1.4 million unregistered workers and family members in an October 2011 report. 

Nationwide, more than 500 people have died in this year's monsoon, with more than seven million households in affected areas, according to the government as of 7 November.

This article was first published in IRIN.