Christmas shoppers on a packed Mong Kok street gasped in pain and screamed for help yesterday as two bottles of acid, apparently thrown from above, crashed to the ground and exploded.
It took a while for the dozens of victims to realise they had been hit by acid, witnesses said. Then they rushed to find water to wash the burning liquid from their faces, eyes and hands.
One man told of seeing one of the plastic bottles hit the ground and liquid burst out.
'A bottle came down,' he said. 'It looked like an ordinary bottle of water, and the crowd began to disperse. Then I saw people with red faces and eyes in pain.'
Victims covered their eyes in pain as they boarded ambulances. Others had holes in their clothing or backpacks. A piece of clothing with holes burned into it was left at the scene.
Some of the victims needed hospital treatment.
The attack happened soon after 5pm near the junction of Sai Yeung Choi Street South and Shantung Street. The pedestrianised Sai Yeung Choi Street South is a shopping hot spot.
The two white bottles, each with a capacity of about 750ml, were kicked by pedestrians after they landed, making it more difficult to determine from where they had been thrown.
Police officers with shields and helmets searched the Chung Kiu Commercial Building and other buildings near the scene, but five hours after the attack they had still not found any suspects.
Police said 46 people had suffered acid burns. Those treated in hospital had been released by 10pm.
Superintendent Annie Fonda of the Kowloon West regional police headquarters said the attack appeared premeditated.
'Traces of caustic liquid were left on the ground,' Ms Fonda said. 'Judging by the traces and the positions of the two bottles, this is not an accident.
'We believe someone intentionally hurled them from a height.'
She said police were concerned about the incident, which crime squad officers were handling.
Sections of both streets were sealed off after the incident, but were reopened last night.