Malaysia has been outraged by the murder of the North Korean leader's estranged half brother at Kuala Lumpur International Airport on Feb. 13 by assassins using VX nerve agent, a super toxic chemical listed by the United Nations as a weapon of mass destruction.
Police have identified eight North Koreans wanted in connection with the murder, including a senior North Korean diplomat and a state airline employee. The only people charged so far are a Vietnamese woman and an Indonesian woman.
As the row escalated on Tuesday, state-run KCNA news agency reported that North Korea's foreign ministry had issued a temporary ban on Malaysians leaving in order to ensure the safety of its own diplomats and citizens in Malaysia. It effectively made Malaysians hostage in the state.
Malaysia reacted promptly. Deputy Prime Minister Ahmad Zahid Hamidi announced a ban on North Koreans leaving the Southeast Asian country with immediate effect.
Zahid later clarified to reporters that only North Korean embassy staff and officials were banned from leaving Malaysia.
Before the murder, North Korea could count Malaysia as one of its few friends, but Malaysia has since stopped visa-free travel and on Monday it expelled North Korea's ambassador for questioning the impartiality of the murder investigation.
There are 11 Malaysians believed to be in North Korea, according to a Malaysian foreign ministry source, including three embassy staff and six family members, plus two others working in the country.
Speaking at a news conference in Kuala Lumpur on Tuesday, Malaysia's police chief said up to three of the North Koreans sought in connection with the murder had holed up at the embassy in the Malaysian capital.
"How much longer do they want to hide in the embassy...it is a matter of time before they come out," police chief Khalid Abu Bakar said.
"We will not raid the embassy building, we will wait for them to come out. We have got all the time," Khalid said.
Police have cordoned off the North Korean embassy in Kuala Lumpur.
Aside from the suspects said to be hiding in the embassy, police have said that four other North Koreans left Malaysia in the hours after the murder.
The only North Korean suspect to be apprehended was deported on Friday, released due to insufficient evidence.
U.S. officials and South Korean intelligence suspect North Korean agents were behind the assassination of Kim Jong Nam, who had been living in Macau under China's protection, and had spoken out publicly against his family's dynastic rule of North Korea.
North Korea has refused to accept that the dead man is leader Kim Jong Un's half brother, and has suggested the victim died of a heart attack.
No next of kin have come forward to claim the body, but the Malaysian police chief said he was confident of obtaining DNA samples to formally identify the murdered man.