Two more suspects have been arrested in connection with the death of Kim Jong-nam, the brother of North Korean leader Kim Jong-un, in Malaysia.
A female Indonesian suspect and a Malaysian man thought to be her boyfriend were both detained on Thursday.
A woman travelling on a Vietnamese passport has also been detained.
Kim died on Monday after apparently being poisoned while waiting to board a flight in Kuala Lumpur.
Police say they have now finished their post-mortem examination, though the results have not yet been made public.
The two female suspects have been remanded in custody for seven days.
The inspector general of the Royal Malaysia police, Sri Khalid Bin Abu Bakar, said the second woman was detained on Thursday over the death of "a Korean male".
She was identified from airport CCTV footage and had an Indonesian passport.
Malaysian Deputy PM Ahmad Zahid Hamidi formally confirmed on Thursday that the dead man, who was travelling under the name Kim Chol, was Kim Jong-nam, according to state news agency Bernama.
There is widespread speculation that North Korea was behind the killing, but there has been no proof.
North Korea is on Thursday celebrating what would have been the 75th birthday of Kim Jong-il, the late leader and father of both Kim Jong-nam and Kim Jong-un.
Kim Jong-un was seen attending a ruling party meeting on Wednesday. Footage aired on state media showed him grim-faced, reported South Korea's Yonhap news agency, and he did not wave when he left, as is customary.
Malaysia 'will return body'
Selangor Police Chief Abdul Samah Mat told the BBC the examination of Kim's body was completed on Wednesday evening, but there has been no indication of whether the results will be made public.
The deputy prime minister said Malaysia would grant a request from North Korea for the body to be returned once police and medical procedures were completed.
Kim is believed to have been attacked in the airport departure hall by two women, using some form of chemical.
A grainy image taken from security camera footage, which has been broadcast in South Korea and Malaysia, shows a woman wearing a white T-shirt with the letters "LOL" written on the front.
It is not clear whether either is the woman in the footage, and police say they are still looking for "a few" other suspects.
Malaysia police said the woman arrested on Thursday was identified in her passport as Siti Aishah, 25, from Banten province in Indonesia.
The suspect arrested on Wednesday had Vietnamese travel documents bearing the name Doan Thi Huong, 28.
A murder mystery: Karishma Vaswani, BBC News, Kuala Lumpur
An alleged assassination attempt, a grainy shot of a woman wearing a T-shirt with "LOL" written on it, and a dead body that has yet to yield any information.
It has all the makings of a murder mystery, with more questions than answers.
Who is the Vietnamese woman the Malaysian police say they've arrested, and what does she have to do with the case?
How is it possible that in a crowded airport, in broad daylight, a man can be accosted with some kind of toxic substance, and no trace of it is left behind at the crime scene?
People I spoke to at the airport who may have seen what happened were reluctant to talk about it, and at least two of them told me that they had been instructed not to talk by police.
Then there's the investigation, which also appears to lack focus.
All Malaysian police officials will tell us is that once they have the results of the post-mortem they will be able to identify what really happened to the man believed to be Kim Jong-nam.
Kim Jong-nam was largely estranged from his family, after being bypassed for inheriting the leadership in favour of his youngest half-brother. He spent most of his time overseas in Macau, mainland China and Singapore.
He had spoken out in the past against his family's dynastic control of North Korea and in a 2012 book was quoted as saying he believed his younger half-brother lacked leadership qualities.
But he had said he was not interested in assuming the leadership himself.
Unnamed US government sources have said they believe he was poisoned by North Korean agents.
South Korean spy chief Lee Byung-ho told South Korean MPs that Pyongyang had wanted to kill Kim Jong-nam for several years, but that he was being protected by China.
The secretive state has a long history of sending agents overseas to carry out assassinations, attacks and kidnappings.
But some analysts question what motive Kim Jong-un would have to kill his estranged half-brother, given the risk of the operation and possibilities for embarrassment, added to the fact that he was not seen as a threat to Mr Kim's leadership.
Still, Kim was reportedly targeted for assassination in the past. A North Korean spy jailed by South Korea in 2012 is said to have admitted trying to organise a hit-and-run accident targeting him.