North Korea and Malaysia have banned each other's citizens from leaving their countries, in a growing row over the killing of Kim Jong-nam,the estranged half-brother of the North Korean leader Kim Jong Un. The tit-for-tat actions come amid North Korean fury at Malaysia's ongoing investigation into his death at a Kuala Lumpur airport. <br/><br/>North Korea's Foreign Ministry has notified the Malaysian embassy in Pyongyang of the reason for the measure and said it had hoped the case would be swiftly and fairly resolved in order to develop bilateral ties with Malaysia. <br/><br/>Malaysian Home ministry said in a statement that no official or employee of the North Korea embassy is allowed to leave the country. Both Malaysia and North Korea have already expelled each other's ambassadors.<br/><br/>The North Korean leader's half-brother was killed with a potent nerve agent. 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.