Security chief Chris Tang said on Wednesday that Hong Kong needs to keep in place its ban on the wearing of face masks at public gatherings because of the national security risks the city faces.

The ban was introduced through emergency laws during the 2019 protests.

At a Legco meeting, lawmaker Stanley Li asked Tang whether people could get away with wearing a mask at a protest if they were sick and had obtained a doctor's note in advance.

In response, the security minister said having a face covering for health or religious reasons was acceptable under the law, but a gas mask or a "V for Vendetta mask" would be another story.

Tang added that the government understands that some people want to continue to wear the masks they were until recently obliged to use due to the pandemic, and this is not a problem.

"[The anti-mask law] only regulates public meetings and public processions under the Public Order Ordinance, as well as unlawful and unauthorised assemblies," he told lawmakers. "It will not affect the wearing of masks by the public in their daily lives."