Sun Sep 30, 6:22 PM ET

MAE SOT, Thailand - The rows of children transfixed by cartoons in a wooden shelter near the Thai-Myanmar border are probably too young to understand why they are all now wearing matching rust-red clothes.

On the wall is a map of their homeland Myanmar, where the ruling junta this week cracked down on anti-government protests and killed at least three Buddhist monks, whose deep red robes the kids are unconsciously honouring.

The four and five-year-olds are probably also too young to fully understand why their parents left their impoverished country, formerly known as Burma, or what forced their mothers and fathers to finally abandon them in Thailand.

"A lot of Burmese people are working here," said Thant Zin Kyaw, deputy director of local assistance group Social Action for Women (SAW), which runs the safehouse for abandoned children.

"They come here for different reasons. Some are facing serious crisis in Burma like forced labour, economic crisis, child labour."

Resource-rich Myanmar was once one of the most economically promising countries in Southeast Asia, but 45 years of military rule have run infrastructure into the ground.

Myanmar is now one of the world's poorest countries with per capita gross domestic product (GDP) well below that of nearby Cambodia, Laos and Bangladesh. UN figures show the junta spends just 0.5 percent of GDP on health.

Seeking a better life for their families, many people from Myanmar illegally cross the porous border to Thailand, but once here they lack access to all social services, and are open to exploitation by employers.

Migrant workers may give up their children because the parents are HIV positive or the child is disabled and they cannot afford to look after them.

Some are not allowed to take the time off work to look after an infant, said Thant Zin Kyaw, as toddlers dressed by the staff in red ambled around a playhouse nearby.

Four-year-old Su Su Aung, who has cerebral palsy, will soon be joining the 32 abandoned children who are living at SAW's safehouse, even though it is already over its capacity of 25.

Currently he lies alone under a mosquito net on the floor of the Mae Tao Clinic, one of the few medical centres in Mae Sot where migrant workers and people coming across from Myanmar can get free health care.

Su Su Aung's parents crossed the border a few months ago and came to the clinic. His mother was treated for malaria, but died when she returned home.

His father soon brought Su Su Aung back and he became one of 10 abandoned children the clinic has treated since 2006. Staff say the man was probably unable to care for a disabled child alone.

Just a few feet away from Su Su Aung lies another infant, now four months old. She was abandoned at the clinic by her migrant worker parents when she was just 13 days old.

"People have no money to look after another child ... Most of the time, (the parents) wait for the staff to be busy, and they run away," said Eh Moolah, a senior medic in Mae Tao Clinic's reproductive health department.

"They say 'I need to go to the toilet, take my baby', and then they run."

The clinic's founder Cynthia Maung says the decision to abandon a baby is a final act of desperation that stems from a lack of access to services as basic as family planning advice.

Humanitarian organisations estimate that there are up to two million illegal Myanmar migrants working all over Thailand.

Although there are humanitarian organisations and clinics such as Mae Tao, which is funded by foreign donors, to help the migrant workers, many are unaware of their services, and fall through the cracks.

Some first-time migrant mothers are so desperate to get help delivering their babies that they will commit a small crime to go to Thai prison, where they receive basic health care, Cynthia Maung tells AFP.

Mae Tao Clinic also treats many migrant and Myanmar women who suffer side effects after illegal abortions, which many undergo because they simply cannot afford to feed another mouth.

Economic ills and the soaring costs of living were key reasons for recent anti-junta rallies in Yangon, and people often risk an illegal border crossing because they are too poor to afford even the paltry health care on offer in Myanmar.

It was poverty that forced San Thaw Dar, now 17, to come from Myanmar's Karen State to Thailand with her mother when she was 11 years old.

She was immediately put to work as a domestic helper, but accidently smashed a doll belonging to her employers, who demanded 5,000 baht (142 dollars). Instead of paying the fee, her mother dropped San Thaw Dar off at the SAW safehouse and left.

Surprisingly, San Thaw Dar does not feel any bitterness towards her mother, but thinks about her homeland, especially as she is not a legal Thai citizen.

"I would like to go back to Myanmar, but it depends on the situation," she said, as the younger residents scrambled over her, as yet in happy ignorance of life as a stateless person.