North Korea is employing land-based sensors along its border with China to detect people trying to flee the country, sources in Seoul said Monday.

Insiders familiar with the reclusive country told Yonhap News Agency that the North's national security agency has set up unmanned detection devices following orders issued by leader Kim Jong-un. 

The North Korean leader has stressed the importance of dealing effectively with defectors as quickly as possible. 

There have been previous reports that the North is using infrared cameras along the Sino-North Korean border, but this is the first time that unmanned sensors have been mentioned as part of Pyongyang's efforts to deal with defectors.

Without providing too many details, the sources said that the sensors have been placed on well-known escape routes, such as Hyesan in Ryanggang Province and around Heoryong in the North Hamgyong region.

"The North plans to increase the number of sensors to better detect defectors and deter those wanting to escape," said a source, who wished to remain anonymous.

He claimed that the North's security apparatus increased the number of agents to ferret out defectors, as well as their support groups, and even resorted to laying "traps" to apprehend them. 

"Security agents even disguise themselves as brokers and contact escapees already in South Korea, and then pretend to help their family members in the North escape, only to arrest them," the insider said.

There have even been reports that defectors and brokers that helped people escape were executed in Ryanggang to spread fear among the populace.

Reflecting this, North Korean groups operating in Seoul said that while there were a steady stream of some 20-30 defectors who successfully escaped the North every month over the border in 2016, this number has fallen off noticeably this year.

Nam Sung-wook, a professor of unification studies at Korea University, said that the North Korean leader views defectors as a weak link in his iron-fisted rule and has made dealing firmly with this issue a top priority as he enters his sixth year in power. (Yonhap)