An alarmed Hong Kong government warns it might impose even stricter social distancing measures to arrest the rapid spread of a COVID-19 "Third Wave" that saw more than 60 confirmed and probable cases on Saturday alone.

The Hong Kong Health Department revealed 16 local infections among 28 cases officially acknowledged on Saturday. It listed another 33 people as probable COVID-19 cases awaiting test confirmation. These new numbers increases Hong Kong's confirmed new case count to 1,431 as of Saturday. In addition, Hong Kong mourns seven deaths.

Twelve of the 28 confirmed infections were imported. Six of the imported cases came from the Philippines. The rest were visitors from Azerbaijan, Germany, France and Turkey.

The raging Third Wave prompted Dr Chuang Shuk-kwan, head of the communicable disease branch at the Centre for Health Protection (CHP), to urge Hong Kongers to stay at home and not go to work, if at all possible. She warned the government will further tighten social distancing restrictions if the surge continues into the next few weeks.

"This third wave of infections is by far the most severe since the epidemic started, even worse than back in March," said Dr Chuang.

More alarming for Dr Chuang and local health authorities is growing evidence this Third Wave is indeed a massive community spread not driven by foreigners visiting the city. She said the number of confirmed cases having unknown sources of infection increased by seven on Saturday to 28. She recalled that when Hong Kong was hit by a surge of cases in March, the daily double-digit increases mostly consisted of imported cases or those linked to traceable sources.

"Now that there are outbreaks affecting restaurants, elderly homes, with some students affected as well as certain areas and some housing estates ... we are concerned about the situation," she pointed out.

Dr Chuang said health authorities expect more cases the Shenzhen area, which is shaping-up to be a new COVID-19 hotspot. Because Hong Kongers are so mobile and travel a lot, "The whole of Hong Kong is facing an outbreak," said Dr Chuang.

Hong Kong acknowledged it had entered a second wave on July 8 when it reported 24 new COVID-19 cases. It said 19 of these cases were local infections while five were imported. This jump prompted Dr. Chuang to declare the existence of a Third Wave.

She said the local government is worried "there will be a massive community outbreak, with so many sources of infection." She said the Third Wave was triggered by an increase in social activities throughout the city since last month. She also believes young people are driving this new wave.