The Under Secretary for Health, Libby Lee, on Saturday said Covid restrictions should not be further eased as case numbers were rising.
She told a TV programme that the daily tally - which has doubled from earlier this month - had not peaked, and relaxing curbs now would worsen the situation.
"To further relax restrictions would be like adding more fuel to the fire... we think [we] should slow down the pace [at which curbs are being eased]," she said.
"Some people say they aren't afraid [of Covid-19]. If you are young and have got four jabs... you don't need to be afraid. But I would like to ask you to take good care of the elderly and children in your family. They may not be as fit as you."
Meanwhile, Dr Lee said requirements for people coming from the mainland did not need to be tightened in spite of rising Covid cases there.
"The control measures on the mainland are known to be cautious. Residents can't leave their neighbourhood in case of an outbreak, so relatively speaking the risk is very low."
The official said only 0.04 percent of arrivals from the mainland had been found to be infected with Covid, while the figure for overseas arrivals was up to 5 percent.
She said when the Covid situation eases, authorities may consider allowing arrivals - apart from those travelling in tour groups - to dine in restaurants during their first three days in the city.
Separately, Chief Executive, John Lee, said he has now tested negative for Covid.
Lee tested positive for the virus on Sunday after returning from a four-day trip to Bangkok.
In a Facebook post, the CE thanked people for their concern. He said he had the occasional cough but was now generally feeling okay.
He again appealed to the public to get vaccinated against Covid as soon as possible to prevent serious complications.