The attack has shocked a city where violent crime of any sort is relatively rare.

Two women were stabbed to death in a Hong Kong mall on Friday afternoon in what appeared to be a random knife rampage – an attack that has shocked a city where violent crime is rare.

The attacker was eventually subdued and arrested after police arrived, the South China Morning Post (SCMP) reported.

Police said they had arrested the 39-year-old unemployed man on suspicion of murder and that the suspect has a history of mental illness.

Friday’s incident was captured on video by a security camera at the Hollywood Plaza mall in Diamond Hill.

The clip shows the attacker pinning one of the women to the floor and repeatedly stabbing her, in an attack that went on for a minute. It also shows the woman’s friend trying to fend off the suspect several times, without success. She 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 multiple injuries.

One of the women was stabbed more than 25 times, but it remains unclear whether the assailant knew both women.

Police senior superintendent Elieen Chung Lai-yee said the suspect purchased the 12-inch knife used in the attack in the same mall, shortly before the stabbing.

“He walked around for a few minutes and then launched his attack on the first victim,” Lai-yee said, adding the second woman came forward to stop him, but became a target herself. “We found multiple knife wounds on (the two women) and they were bleeding profusely.”

Footage circulating online shows the attacker buying a knife from a shop about 10 minutes before his rampage.

Hong Kong’s leader, Chief Executive John Lee, said in a statement Saturday that he was saddened by the attack and had sent condolences to the two women’s families.

The former police officer also urged citizens to stop sharing footage of the attack online and advised the public to “seek professional support if they experience any emotional distress.”

“This is an isolated case,” Lee said.

The attack has shocked a city where violent crime of any sort is relatively rare, particularly so because of the apparently random nature of the incident.

Hong Kong sees only a few dozen homicides each year, compared to several hundred in New York. Last year, it recorded only 77 robberies, compared to more than 17,000 in New York and 24,000 in London.