A psychiatric patient has been arrested on suspicion of throwing five chairs from his 33rd-floor flat in a Yau Tong public housing estate yesterday, in the second such incident in three days.
No one was injured, a police spokeswoman said.
In Tuesday's incident, a passer-by was killed after being hit by an office chair that was allegedly hurled from the roof of a 10-storey Mong Kok building.
In yesterday's case, a wooden chair, two folding chairs and two plastic stools crashed down from Ko Lun House at Ko Cheung Court on Lei Yue Mun Road shortly before 9am, police said.
One stool and a foldable chair smashed onto the ground floor outside the building, while the rest landed on the first-floor canopy. Officers arrested a 23-year-old man during door-to-door inquiries, the spokeswoman said.
An initial investigation indicated the jobless man was an outpatient at United Christian Hospital's psychiatric section in Kwun Tong, a police source said.
"He was alone when our officers arrived," the source said. "His 55-year-old mother had gone to the market to buy food at the time of the incident."
The man received regular visits from an outreach psychiatric nurse, United Christian said. His last consultation was on June 4, with the next due on July 2. He was taken to Kowloon Hospital's psychiatric department, where doctors would assess his mental state, the source said.
Police said they had not received any reports of domestic violence involving the family, who lived on welfare. Last night, the man had not been charged.
The suspect in Tuesday's incident, Tong Mong-leong, was absent from Kowloon City Court yesterday. Tong, 22, is charged with one count of murder over the death of salesman Wong Wai-tik, 29, at Sai Yeung Choi Street South. The court heard Tong was still in hospital and adjourned the case to Monday.
Tong, a former waiter, is an outpatient at Kwai Chung Hospital, a psychiatric facility. He turned up for a consultation last Friday and was to return on July 4, the hospital said.
University of Hong Kong psychiatry clinical professor Eric Chen Yu-hai said he did not rule out the possibility that the second chair-throwing patient had copied the first, although that would not be a common pattern.
"The way that people with psychiatric problems process news could be beyond our thinking," Chen said.
The heavy patient load for psychiatry at public outpatient clinics meant doctors had only a few minutes to see each patient and might fail to detect any strange behaviour, he said.
Irene Chau, a housewife who lives near Ko Lun House, said she saw the fallen chairs yesterday morning. "Of course I'm worried," she said. "We all feel fortunate that no one was hurt. We'll walk on sheltered paths to keep safe, even if it is a longer route."
Another housewife, who lives in Ko Lun House, said all kinds of things had been tossed out of the building in the past, including wrapped faeces and sanitary pads.
Additional reporting by Julie Chu