MizzimaAuthorities in China have detained more than 400 Myanmar migrant workers for more than a year for entering the country illegally and working without official documents, according to RFA.

About 300 of the migrants were held at a prison in the southern coastal city of Dongguan, while the rest are detained inside a seafood factory in the city of Weihai, Shandong province, a peninsula that juts eastward into the Yellow Sea.

The 400 workers are among a pool of some 230,000 migrants who have sought work in China in the wake of armed conflict, environmental destruction and natural disasters in Myanmar, the Mekong region’s largest source of migrants, according to the U.N.’s International Organization for Migration.