Malaysia has recalled its envoy to Pyongyang in an escalating row over the killing of Kim Jong-nam, the half-brother of North Korea's leader Kim Jong-un.
Kim Jong-nam died in mysterious circumstances last week at a Kuala Lumpur airport - police believe he was poisoned while waiting for a flight.
Malaysian police say they are now looking for four North Koreans.
Pyongyang's envoy to Malaysia was also summoned over earlier comments he made.
Last week Kang Chol accused Kuala Lumpur of colluding with "hostile forces" and said that Malaysia had "something to conceal", allegations that provoked an angry response from Malaysian authorities.
Despite widespread speculation that North Korea was behind the killing, there has been no definitive evidence and Pyongyang has made no public comment on the issue so far.
So far Malaysian police have detained one North Korean suspect, Ri Jong-chol, and said they are looking for four more men, who may have already left the country. Two women, an Indonesian and a Vietnamese, have also been arrested.
Malaysia was one of very few countries to maintain diplomatic relations with North Korea, but this killing has strained ties.
Over the last week Malaysia has refused to accede to North Korean demands to release Mr Kim's body into their custody without an autopsy.
A Malaysian foreign ministry spokesman said on Monday that their Pyongyang ambassador had been recalled "for consultations".