Interpol has put out “red notices” for four North Koreans wanted in connection with last month’s assassination of the half-brother of North Korea’s leader in the Kuala Lumpur area, Malaysia’s police chief said Thursday.

Malaysian authorities had asked the international police organization to help them catch the four men who are believed to have fled Malaysia on the day Kim Jong Nam was killed in a chemical attack at a local airport, Police Inspector-General Khalid Abu Bakar said.

“We have obtained the red notice for the four North Korean men who were at the airport during the incident,” Khalid told journalists in Putrajaya.

“We believe they have since left for Pyongyang. We are hoping to get them through Interpol,” he added.

A red notice is a request among Interpol’s member states to locate and provisionally arrest a person, pending their extradition. However, North Korea is not a member of the organization.

Interpol, based in Lyon, France, has posted red notices on its website for the four North Koreans, listing each as being wanted by Malaysian authorities for prosecution on murder charges, but without giving much more information. It identified the four as Ji Hyon Ri and Song Hak Hong, both 32; Jong Gil O, 54; and Jae Nam Ri, 56.

The four were filmed by a closed-circuit TV camera as they observed the assassination unfold at Kuala Lumpur International Airport 2 on Feb. 13, when two Southeast Asian women accosted Kim Jong Nam in the departures lounge and smeared a deadly nerve agent on his face, according to Malaysian police.

The suspected female assassins have been arrested and charged with Kim’s murder. In addition to the four men listed by Interpol, Malaysian police have identified three other North Koreans as suspects in the case, and who are believed to be hiding out in Pyongyang’s embassy in Kuala Lumpur.

Malaysia’s prime minister has openly accused North Korea of being behind the assassination. Officials in South Korea and the United States have also blamed government agents from Pyongyang for orchestrating the murder, in which Kim was killed with a banned chemical classified by the U.N. as a weapon of mass destruction.

‘They have given consent’

The killing has led to a bilateral row between Pyongyang and Malaysia over Kuala Lumpur’s initial refusal to hand over Kim’s body to North Korea without a post-mortem, and unless his next-of-kin came forward to give DNA and claim the body.

On Thursday, Malaysian Deputy Prime Minister Ahmad Zahid Hamidi disclosed that officials had travelled to another country to obtain DNA samples used to positively identify the dead man as Kim Jong Nam, and that these were collected from his 21-year-old son, Kim Han Sol.

“From the son, who is out of the country,” Zahid said, declining to name the country. “I would like to confirm that the DNA has been taken and brought to Malaysia and it is indeed Kim Jong Nam.”

Meanwhile, Malaysia’s deputy police chief indicated Thursday that Kim’s family had given its approval to Malaysian authorities to decide what to do with his embalmed remains, but the official did not make it clear whether the family wanted to take possession of the body.

“They have given consent to the government on what to do with the body. It is up to discussion and negotiation. We cannot just simply make a decision. You have to wait,” Deputy Police Inspector-General Noor Rashid Ibrahim told reporters.

“When negotiations are completed and both agree to term we will announce it,” he said, referring to bilateral efforts under way to resolve the diplomatic dispute, which has seen both countries expel their respective envoys and impose exit bans on each other’s citizens.

On Wednesday, Zahid, the deputy PM, said Malaysia was “looking at all possibilities,” including handing over Kim’s body to North Korea in exchange for nine Malaysian citizens trapped in Pyongyang because of the exit ban.