Up to 1,000 Burmese detained in the Thai border town of Mae Sot after they escaped extensive flooding are struggling to access food and water, with Thai authorities accused of exploiting the thousands of migrants attempting to flee back to their home country.

Reports began to emerge last week of police arresting Burmese migrants as they made their way to the border, having been displaced by Thailand’s worst flooding in 70 years. Upon arrival in Mae Sot, which lies opposite the Burmese town of Myawaddy, a number were detained at the immigration lock-up.

“Since there are a lot of people, there isn’t enough space and food so the migrants are not given a meal or any water,” said Sutthisak Runprueang Phasuk from the Thailand-based Migrant Assistance Programme (MAP), which has visited detainees over the past week.

While they are permitted to buy supplies from a shop in the detention centre, Sutthisak said, most have little money and therefore are struggling to find food

The majority are kept in the lock-up temporarily before being sent across the border by Thai police. Their problems don’t stop there, however, with many forced to go through checkpoints run by a local government-backed Border Guard Force, which charges up to 4,000THB for re-entry.

Those who cannot afford the fee return to Mae Sot, where they again face possible arrest.

A female migrant worker, who worked in the construction industry in Pathum Thani province, north ofBangkok, said she came to Mae Sot in a truck operated by brokers, who charged a fee of 4,000THB.

Migrants whose registration papers dictate they cannot travel outside of permitted zones in Thailand have been forced to use clandestine brokers to carry them out of flood-affected areas.

The confirmed death toll from the floods now stands at 381, with two missing. Millions are attempting to flee Bangkok and surrounding provinces, with Reuters saying on Sunday that vehicles were bumper to bumper for around 12 miles on an elevated road out of Bangkok.

Floodwaters have submerged an area the size of Kuwait and destroyed nearly a quarter of Thailand’s rice crop. The Bangkok Metropolitan Authority says the amount of rainfall this year has been 40 percent higher than average.