Two women were stabbed to death in a Hong Kong mall on Friday, in what appeared to be a random knife rampage.
The attacker was eventually subdued and arrested after police arrived, according to the South China Morning Post (SCMP).
The incident was captured on video by a security camera at the Plaza Hollywood mall in Diamond Hill.
It shows the man going up to the women from behind shortly after 5pm local time.
In the clip, he repeatedly stabs one of them in an attack that went on for nearly a minute, SCMP said.
The second woman attempts to intervene several times, but is also attacked. Nobody goes to the women’s rescue.
Police said the women were aged 22 and 26.
They were unconscious when they were taken to hospital, where they succumbed to their injuries.
One of the women was stabbed more than 25 times.
It remains unclear whether the attacker knew the two women.
A saleswoman at the mall said the assailant stood beside the two victims as mall medical workers arrived at the scene to provide first aid. The police arrived shortly after.
“There was no sign the medics knew the assailant was next to them,” the saleswoman said, adding that staff were still “clueless about what had happened” when the mall notified shops to close.
The area was cordoned as officers carried out an investigation.
Footage that has since circulated online shows the 39-year-old attacker buying a knife from a shop about 10 minutes before his rampage.
Another video clip shows a team of police officers, armed with shields and pepper spray, approaching the man. They order him to drop the 15cm knife.
The officers eventually rush at him together, drag him to the floor and handcuff him.
The attacker has been taken to a police station for questioning.
The authorities have classified the case as murder.