The North Koreans are travel secretly on what is becoming known as a new underground railroad through China, Laos and Burma.
When they reach the Mekong river, on Thailand's northern border, the cross into the country before being sent to South Korea.
Presenter: Jared Ferrie
Speaker: North Korean refugee (name withheld); Tu Shanaroon, guesthouse owner in Chiang Saen, Thailand
FERRIE: On the side of the road in Northern Thailand, three families of North Korean refugees stop to rest. They've just crossed the Mekong River into Thailand after traveling about 3,000 miles through China and Laos. But now they aren't sure exactly where they are. One of them speaks a little English and she tries to find directions to get to Bangkok.
NORTH KOREAN REFUGEE: From Bangkok, what kilometer? Eight hundred? Yes, yes. Call taxi, call a taxi?
FERRIE: The refugees have arrived too late to catch a bus, and they would likely be caught at a police checkpoint if they did. Instead, they trudge into the small riverside town of Chiang Saen
FERRIE: After about an hour of walking they've arrived at the local police station
FERRIE : The Chiang Saen police have gotten used to these arrivals. North Korean refugees started trickling into town a few years ago. But now they arrive much more frequently.
SHANAROON: I see many times. In cold season, almost every day.
FERRIE: For the past 35 years Tu Shanaroon has run the Chiang Saen Guesthouse right along the riverfront. Just last week she saw a group of refugees passing by and they asked her for a place to sleep. But it would have been illegal for her to provide lodging to people without Thai visas.
SHANAROON: I know Chinese a little but, I talk with them a little bit. They told me that they come from North Korea and then they stop in China. Then they take the boat from China and stop in Laos. In Laos they take the boat from over there, not far from Golden Triangle, and they take a speed boat. And Golden Triangle they walk to Chiang Saen.
FERRIE: They cross into Thailand at the Golden Triangle, which is the area where the Thai, Lao and Burma borders meet. After crossing the river, they make their way into town.
The local police are struggling to accommodate the rising number of refugees. In 2004, only 46 North Korean migrants were detained in Thailand. The number rose to 2,500 last year with most arriving in this area.
The police do not want to speak to journalists about the issue, but it is clear that they have their hands full. This group of refugees joined about ten that were already being housed in a building in the police compound.
The South Korean government appears to have made an unofficial deal with Thailand to take recently arrived refugees. After Thai authorities process the refugees, the South Korean government buys them plane tickets to Seoul.
The journey from North Korea is a long and dangerous one. Sometimes Christian groups help smuggle North Korean defectors into Thailand. But others are forced to pay human traffickers about 30,000 us dollars. To raise the deposit on the trip, many need to work along the way.
One of the women in this group says she spent five years in China. As illegal workers they often face abuses, and they are constantly under threat of being detained by the Chinese authorities.
But once they make it to Thailand, the North Koreans are usually safe. After crossing over from Laos, this walk into town is one of the final legs of their journey to freedom.