Kim Jong Nam, the half-brother of North Korea's supreme leader Kim Jong Un, has been assassinated on Feb. 13 and detectives are already pointing to four suspects in the case. As the investigation continues for the Kim Jong Nam assassination, more North Korean nationals are being linked and asked for questioning regarding the brazen killing of Kim Jong Il's eldest son.

Two people who were arrested in connection with the Kim Jong Nam assassination are being held by the Malaysian authorities since the assassination happened at the Kuala Lumpur International Airport. The suspects caught include two women who were identified as an Indonesian and a Vietnamese national.

Noor Rashid Ibrahim, Malaysia's deputy inspector-general of police, said that they are currently on the hunt for four other North Koreans who are now on the run. The police chief revealed that the suspects for the Kim Jong Nam assassination landed separately in Malaysia, arriving on different dates starting Jan. 31.

However, these people immediately flew out of the region on Feb. 13, the same day when the Kim Jong Nam assassination happened. One of the women in custody stated that she was only tricked into spraying something on Kim Jong Nam, claiming that she thought it was part of prank for a TV show.

The Sun Daily reported that Malaysia's Royal Police Chief Khalid Abu Bakar immediately dismissed this theory. "Of course they knew it was a poison attack," he said. "If you have seen the video, the lady was moving away with her hands towards the bathroom. She was very aware that it was toxic and that she needed to wash her hands."

The police chief added that the suspects for the Kim Jong Nam assassination, Vietnamese Doan Thi Huong and Indonesian Siti Aishah are trained killers. The latter wiped the poisonous substance in Kim Jong Nam's face then the former sprayed something after. For the police, the moves were clearly a well-rehearsed attack.

The other North Korean suspects are believed to have returned to Pyongyang already while the rest are in hiding somewhere in Malaysia. One of the new suspects is a North Korean diplomat named Hyon Kwang Song. He was said to be the supervisor of the whole Kim Jong Nam assassination plot and he could be hiding at the North Korean embassy in KL where he works.

Meanwhile, Reuters reported that the U.S. and South Korean officials believe that North Korea was behind the Kim Jong Nam assassination. The suspicion heightens when diplomats in Kuala Lumpur are preventing an autopsy on the 46-year-old's body and rather making demands to hand over the remains to them.