Three people were injured, one of them critically, after a knife wielding man attacked them near a Lennon Wall in Tseung Kwan O in the early hours of Tuesday.
The police said in a media briefing on Tuesday afternoon that a 50 year-old man was stopped at the Lowu crossing, and arrested on suspicion of assault occasioning actual bodily harm.
Authorities say the attack took place at around 1.30am, and officers have recovered two choppers from the area.
A video circulating on social media showed chaotic scenes at a pedestrian tunnel near King Lam Estate where anti-extradition protesters had put up a so-called Lennon Wall, made up of stickers and posters put up by supporters of the ongoing agitation.
A witness said a middle-aged man started attacking three people with a meat cleaver, after arguing with them over the Lennon Wall.
She said the attacker later fled towards Chung Ming Court, a housing estate nearby.
The police said a 24-year-old man and two women aged 26 and 35 suffered knife wounds. The younger woman, with more serious injuries, was taken to Queen Elizabeth Hospital for treatment.
Police later said the 26-year-old had suffered wounds on her neck and back and was in a critical condition. The other woman was stable, while the man was discharged from the hospital.
Last updated: 2019-08-20 HKT 16:16