The number of North Koreans attempting to leave the country via China increased in the new year, and the country is cracking down on defectors, according to DailyNK.

The news organization uses “underground stringers”  in North Korea and several of its sources told the outlet that arrests were up as people are tried to leave the country.

“The border authorities seem extremely busy lately as the number of arrests of attempted defectors has increased over the last year. Specifically, there has been at least a 150% rise in arrests over the same period last year in Ryanggang Province,” a source told DailyNK. “Last January, 30 to 40 people were arrested in the first couple weeks of the New Year, but this year, 20 people were arrested on Jan. 1 alone. Combined with the number of people being caught in China and repatriated, there are reports of insufficient space to hold them all in the prisons and interrogation centers.”

Even though most defectors leave North Korea through China, it's a treacherous place to defect. People leaving North Korea have to avoid authorities on both sides of the border— defectors caught in China are often returned, and then punished.

North Korean authorities encourage people to report suspicious activities of their neighbors — including defection plans. North Korean authorities are also cracking down on defectors and stepping up surveillance along the border with China.

“Surveillance and the border crackdown has continued to intensify since Kim Jong Un came to power. They are hoping to further discourage defections by heavily promoting propaganda using individuals who have returned to North Korea after having defected to the South,” said Ahn Myung Chul, head of non-profit North Korea Watch to DailyNK.

Last year saw the lowest number of defections to South Korea since Kim Jong Un took over the country. A Jan. 5 report from South Korea’s Ministry of Unification showed that 1,127 people came to South Korea from North Korea, and 83 percent of them were women.

While defections were down overall, rare military defections across the demilitarized zone (DMZ) were up — four North Korean soldiers defected to South Korea in 2017. A harrowing escape for one soldier in November ended in a hail of gunfire. The soldier was hit several times and had to be hospitalized. Another soldier defected across the heavily guarded DMZ in December.

DMZ South Korean soldiers stand guard at the border village of Panmunjom between South and North Korea at the Demilitarized Zone (DMZ) on February 27, 2013 in South Korea. Photo: Chung Sung-Jun/GETTY