BANGKOK • The number of North Koreans slipping illegally into Thailand has surged in recent months, according to immigration bureau officials, as tensions mount on the Korean peninsula because of Pyongyang's weapons programmes.
Thailand is on a popular transit route for North Koreans defecting from the impoverished communist state.
Hundreds flee each year to China and make it to Thailand after an overland journey, from where they are usually sent on to South Korea.
Last year, there were 535 North Korean arrivals in Thailand, but the first six months of this year saw 385 arrivals, according to data from Thailand's immigration bureau seen by Reuters, and more are arriving each week.
"An average of 20 to 30 North Koreans arrive each week now in northern Thailand alone," said an immigration official, who spoke to Reuters on condition of anonymity.
The surge has come despite tighter controls by North Korea on its border with China. It coincides with rising tensions on the Korean peninsula over Pyongyang's stepped-up nuclear and missile tests, and warnings by the United States that it is losing patience with the isolated state.
However, Citizens' Alliance for North Korean Human Rights, a Seoul-based non-governmental organisation, said the number of North Korean defectors coming to South Korea had not increased this year, implying that those coming through Thailand could be making up a higher proportion of the total.
South Korea's Unification Ministry said 593 North Korean defectors had come to the South in the first six months, against 1,418 last year and 1,275 in 2015.
Most North Koreans enter Thailand at its northernmost tip near the Golden Triangle, from neighbouring Laos, the Thai immigration officials said, but new routes have emerged further south.
Unofficially, arrangements are often made between the Thai authorities, the South Korean government and defectors on the ground.
Mr Roongroj Tannawut, a district official of Chiang Khong district near the Golden Triangle, said: "The North Koreans come to Thailand to get arrested so they will get asylum in South Korea."