North Korea has said it is banning any Malaysians currently in its country from leaving, in a growing diplomatic row over the killing of Kim Jong-nam.The state news agency KCNA said the ban would stay in place "until the incident that happened in Malaysia is properly solved".Mr Kim, the estranged half-brother of North Korea`s leader, was killed in Malaysia last month. North Korea has denied accusations that it carried out the killing.It has also been fiercely critical of the Malaysian investigation into Mr Kim`s death, and has rejected the findings of a post-mortem examination which ruled he had been killed with VX nerve agent, the most potent of all known chemical weapons.Pyongyang has also not yet confirmed that the body is that of Kim Jong-nam, acknowledging him only as a North Korean citizen. Mr Kim was travelling using a passport under a different name.While Malaysia has not directly blamed North Korea for the attack, there is widespread suspicion Pyongyang was responsible.Several North Koreans are being sought by police in connection with the killing. Two women - one Indonesian and one Vietnamese - have been charged with murder.Both Malaysia and and North Korea have now expelled each other`s ambassadors. Source: BBC