Police are offering a $100,000 reward for information on the December 13 acid attack in Mong Kok.

About 5.15pm that day two plastic bottles were thrown from a building on Sai Yeung Choi Street South near Shantung Street. Forty-six people aged 14 to 53 were burned by the fluid and taken to hospital for treatment.

The case has been classified as throwing corrosive fluid with intent to do grievous bodily harm.

Anyone with information should contact Police on 2398 6200 or by email here. The reward is valid until June 15.