Two women suffered minor skin burns after acidic fluid dripped on them while walking down a Mong Kok street early on Wednesday morning.
The pair were walking past 2M Nelson Street at around 5am on Wednesday when they heard a noise from the canopy above and felt fluid falling on them, according to the police.
Police officers are investigating the source and nature of the fluid. One possibility was that the fluid leaked down from broken pipes said Allen Poon Wan-chin, Mong Kok district chief inspector.
Two years ago, there were several instances in which bottles containing acidic fluid were thrown onto Sai Yeung Choi Street South in Mong Kok, injuring dozens of pedestrians.
The two women involved in Wednesday incident were sent to Kwong Wah Hospital to have their wounds washed. One had burns on her arm and thigh, the other on her finger.
Police closed a part of the pedestrian zone outside Lok Yuen House, a residential building on Nelson Road on Wednesday morning.