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On Wednesday night and Thursday morning, Malaysia arrested two more suspects in the assassination of Kim Jong Nam, the estranged older half-brother of North Korean ruler Kim Jong Un. The female arrested early Thursday was identified as Siti Aishah, 25, traveling on an Indonesian passport, and the male, believed to be her boyfriend, gave police information that led to her arrest, Malaysian police official Abdul Sama said Thursday. Earlier Wednesday, police arrested Doan Thi Huong, a 29-year-old woman carrying Vietnamese travel documents, at the same Kuala Lampur airport terminal where Kim was murdered on Monday. Police are still searching for four male suspects.

Both women were positively identified in CCTV footage — Huong wearing an "LOL" shirt — and suspected of carrying out Kim's murder with liquid poison delivered either through needles or a spray applied to Kim's face while he was waiting in line for a flight to Macau, his home base in exile. South Korea says the assassination was almost certainly ordered by Kim Jong Un, who issued a "standing order" to have his brother killed after he took power in 2011, South Korean spy chief Lee Byung-ho told lawmakers in Seoul on Wednesday. Kim Jong Nam had survived at least one assassination attempt, in 2012, Lee added.

But many questions remain in the odd case, including what exactly killed Kim — Malaysia finished an autopsy on Wednesday night, over North Korea's objections, but hasn't released the results — and why two suspected North Korean assassins had been captured so easily and didn't even have a get-away car, relying on taxis. Huong reportedly told police that she was tricked into the murder, thinking she was just playing part in a prank then abandoned by the other women and four men still sought by police. You can learn more about the intrigue, and North Korea's history of assassination attempts, in the CNN report below. Peter Weber