HONG KONG, Feb. 9 (Xinhua) -- Hong Kong's Centre for Health Protection (CHP) reported on Sunday three additional confirmed cases of novel coronavirus infection, including two patients believed to be infected in a family party, warning of possible outbreak in families.

File photo: CGTN

The two patients, a 24-year-old man and his grandmother, attended a party with 17 relatives and friends on Jan. 26 in Hong Kong's Kwun Tong district. The preliminary test results of seven of the relatives and friends also showed positive for novel coronavirus.

The CHP is investigating into the source of illness to see if these cases should be classified as a family outbreak, said Chuang Shuk-kwan, head of the CHP's Communicable Disease Branch.

The other additional case confirmed on Sunday involves a 70-year-old man with underlying illness. He lives in Hong Kong's Ngau Chi Wan area, and had no travel history during the incubation period.

Chuang warned at the CHP's daily press briefing on Sunday afternoon that it is difficult to identify locally infected patients and trace their contacts, and people with respiratory symptoms should avoid going out and attending parties.

The three additional cases have brought the total number of confirmed cases of novel coronavirus infection in Hong Kong to 29.

Apart from one death case, the other 28 patients are currently under treatment in isolation at several different hospitals. Three of them are in critical condition, while one is in serious condition, Chief Manager of Hong Kong's Hospital Authority Lau Ka-hin said at the briefing.

Considering that the community infected cases are increasing, the Hospital Authority will significantly adjust non-emergency non-essential services at public hospitals in the coming four weeks to reduce the risk of cross infection, Lau said.