One woman was killed and three other people wounded on Tuesday in a shooting at a Hong Kong park next to a busy shopping centre, a rare gun attack in a city ranked as one of the safest in the world.
A 44-year-old woman was arrested for murder and attempted murder by police in a nearby mall and a pistol was seized, the police said in a statement.
The police added that initial investigations revealed it had been "a dispute with the deceased and the three victims, during which the woman shot them with a pistol."
The dead woman was identified by local media as the 80-year-old aunt of the attacker.
Television stations also showed an elderly man lying on the ground beside a pool of blood and another person with a head wound. The police said the attacker was caught in a mall next to the park.
Two men are in critical condition, including a 62-year-old who was shot in the head. Another woman is in stable condition.
Local media said the suspect and the victims were two brothers and sisters involved in a dispute over an inheritance.
It wasn't immediately clear how the woman had come to possess the handgun. Hong Kong strictly controls the possession of firearms and guns aren't generally available to the public.
Shootings have been rare in recent years, although Hong Kong has in the past seen a spate of bloody armed robberies and shootouts between organised criminal gangs, or triads, and the police.
Scores of police officers with guns and bullet-proof vests had earlier descended on the largely residential area.
The shooting took place in the mid-afternoon in Quarry Bay, to the east of the Central district on Hong Kong island, in a park next to Cityplaza shopping centre.
Dozens of police cars lined the roads and part of the leafy waterfront park was cordoned off.
The leader of the Chinese city, Carrie Lam, said the former British colony, which returned to Chinese rule in 1997, is safe, with a crime rate of 758 cases per 100,000 people in 2017.
"Cases involving firearm and assault are very, very rare, so we are paying great attention to this case involving a firearm hurting other citizens," she told reporters.