North Korean leader Kim Jong-un has ordered his public security staff to hunt down and punish those who leak the reclusive state's internal information to South Korea, multiple sources said Sunday.

In a directive sent to the security agencies and the people, Kim warned that those who leak any information to South Koreans will be labeled as "spies" and face harsh punishments, including execution by firing squad.

"I understand that (Kim) has sent a directive to the security agencies and the people, which says he will sternly deal with rebellious impure elements that hand over our internal intelligence to enemies," a source said, declining to be named.
 

The directive also urges North Koreans who have attempted to make phone calls with those in China and South Korea to turn themselves in to the security authorities, and offers rewards to those who report any intelligence leaks to the authorities, according to the sources.

After the directive was issued, the communist state's security staff beefed up its inspections along the border with China, the sources said.

"In the past, those who were caught making phone calls with people outside the country could be set free with some kickbacks,"

a source said. "But now, they could be executed, and even their families could be punished."

North Koreans are known to contact their relatives in China or in South Korea with phones that they borrowed from Chinese operating within the North or with illegal Chinese-registered phones that they smuggled across the border with China. (Yonhap)