Malaysia is ending visa-free travel for North Koreans because of security concerns, as the fallout continues over the assassination of the North Korean leader’s half-brother at Kuala Lumpur’s airport. Deputy Prime Minister Ahmad Zahid Hamidi announced the end to the visa-free travel rules on Thursday, a day after two women were charged with murder for smearing nerve agent VX on Kim Jong Nam’s face on Feb. 13. The women, identified as Vietnamese citizen Doan Thi Huong and Indonesian Siti Aisyah, have reportedly insisted they thought they were taking part in a television prank, unaware that the chemical they were given was a nerve agent. They face a death sentence if convicted. Malaysian police have identified another suspect in the brazen killing as a North Korean diplomat, amid widespread suspicions that the Pyongyang regime ordered Kim Jong Nam’s murder. Malaysia’s attorney general announced Thursday that a separate North Korean man would be released from custody and deported, according to the Associated Press. The new visa requirements for North Korea will take effect March 6, Malaysian state media reported.