Seoul: 4 N. Korean spies involved in Kim killing in Malaysia

Journalists gather at the main gate of North Korean Embassy in Kuala Lumpur, Malaysia, Monday, Feb. 27, 2017. Malaysia's health minister said Sunday that the dose of nerve agent given to North Korean ruler Kim Jong Un's exiled half brother was so high that it killed him within 20 minutes and caused "very serious paralysis." (AP Photo/Daniel Chan) (The Associated Press)

A police officer patrols outside the forensic department at Kuala Lumpur Hospital in Kuala Lumpur, Malaysia, Monday, Feb. 27, 2017. Malaysia's health minister said Sunday that the dose of nerve agent given to North Korean ruler Kim Jong Un's exiled half brother Kim Jong Nam was so high that it killed him within 20 minutes and caused "very serious paralysis." (AP Photo/Daniel Chan) (The Associated Press)

South Korea's intelligence service says four North Korean government spies were involved in the killing of North Korean ruler Kim Jong Un's estranged half brother.

Lawmakers cited the National Intelligence Service as telling them Monday that four of the North Korean suspects searched by Malaysian police over the Feb. 13 death of Kim Jong Nam are from the Ministry of State Security, the North's spy organ.

The NIS was also quoted as saying in a private briefing that the involvement of the North Korean spies is evidence that the Pyongyang government was behind Kim Jong Nam's death.

Lawmakers didn't say how the NIS got the information.

Malaysia hasn't directly accused North Korea of having masterminded the Kim Jong Nam killing but is pursuing several North Korean suspects over the incident.