Health authorities on Thursday said they suspect a new local Covid-19 case with no known source has emerged in the city, even though the victim had travelled abroad recently, while Nepal Airlines has been banned from flying here for two weeks after nine people who arrived on the same flight tested positive for coronavirus.
A 38-year-old woman who travelled to Europe last month is among the 11 cases that was reported, but officials believe that she contracted the virus in Hong Kong.
The woman had visited Italy and Switzerland from September 5 to 16 and was put under home quarantine for two weeks upon her return.
During that time, she tested negative for the virus twice.
She developed a low-grade fever on October 9 and took some medicine.
The fever subsided, but 10 days later she noticed that she had lost her sense of taste. She visited a private doctor and was subsequently confirmed with the infection.
Dr Chuang Shuk-kwan of the Centre for Health Protection said tests would be carried out to verify the source of infection.
"She has a travel history more than one month ago before she had onset of symptoms. Although sometimes there may be a very long incubation period, the chance is not very high.
"We have locally acquired cases every now and then in Hong Kong, so we can't exclude that she's acquired the disease locally," Chuang said.
The woman lives in Tung Chung and goes jogging every day in the area.
She often went to a market in Tuen Mun for grocery shopping, and had meals at a number of restaurants in Tung Chung and Tuen Mun.
Her son started having a mild cough last Friday but had continued to go to school. He has been taken to a hospital for tests.
The primary school in Tuen Mun that he attends has been asked to suspend classes and carry out disinfection as a precaution, pending the boy's test results.
There were also 10 imported cases on Thursday: nine arrivals from Nepal and one from Pakistan.
Chuang said in view of these cases, authorities have banned flights operated by Nepal Airlines from coming to the SAR until November 4.