When asked by the reporters whether the number tags measures will be extended to all the protest marches in the future, Lee said the authority would make full consideration before demonstrators apply for a rally to ensure all the public gatherings proceed in an orderly, safe and lawful manner.

"We have to be careful that any public gathering will not be either hijacked or turned into troubles that will cause not just inconvenience, but risks to public order, public safety and also national security," Lee said.

Around 80 residents from a homeowner committee in Tseung Kwan O launched a demonstration last Sunday against a government's reclamation proposal for constructing or relocating the obnoxious facilities.

Participants were required to wear number tags and march without masks. The four-hour rally was also closely monitored by the police, with the headcount of protesters restricted to no more than 100.

"It was unnecessary and extremely insulting," said the rally's organiser and convener of the Concern Group for Tseung Kwan O People's Livelihood Cyrus Chan Chin-chun in a radio programme yesterday.

He added that the restrictions were issued with the aim of stopping people from participating in demonstrations, and it would be difficult for Hongkongers to organise protests again if such rules were in place.