SEOUL--North Korea has hired former KGB agents as “military advisers” to bolster protection of leader Kim Jong Un against assassination attempts by the United States and South Korea, a source said.

About 10 or so former KGB agents who once worked in a division tasked with taking down terrorists were invited to Pyongyang in February, according to the source knowledgeable about affairs in the North Korean capital.

They were asked to train Kim’s bodyguards, including how to detect possible terrorist acts beforehand and how to counter such threats when they occur.

The source said North Korean officials were especially interested in guarding against assassination attempts by the United States using some of its most advanced weapons.

One weapon in particular that has attracted the attention of North Korean officials is the Gray Eagle attack drone, which the U.S. military based in South Korea is planning to deploy in early 2018.

In addition, Pyongyang is concerned about plans by the U.S. military and CIA to set up a division that will exclusively handle human intelligence activities in North Korea.

Pyongyang likely expects the former KGB agents to hand down methods of cracking down on spies within the country to strengthen protection of Kim.

A North Korean statement issued in May 2017 accused South Korea’s National Intelligence Service (NIS) of cooperating with the CIA in plotting an assassination of Kim by seeking cooperation of North Korean workers in June 2014.

In June 2017, the NIS issued a report to the South Korean National Assembly, saying the North Korean leader had cut back on public appearances over fears of assassination attempts.

With the collapse of the Soviet Union, the KGB was dismantled and replaced by a new state security apparatus in Russia.