Family clusters of novel coronavirus cases have made up nearly 20 percent of all confirmed cases so far in Beijing, according to a senior health official from the capital on Friday.

As of midnight on Thursday, 77 clusters of infection cases of novel coronavirus were reported in Beijing. Among them, 70 cases were infected by family members, said Pang Xinghuo, deputy director of the Beijing Center for Diseases Prevention and Control, at a daily media briefing by the city's municipal government regarding efforts to contain the virus' spread.

"Multiple family clusters of infection cases occurred in Beijing recently, and it's vital to put every citizen under quarantine at home for protection," she said, adding health conditions of the elderly and children should be given particular attention, as seniors with other diseases are much easier to get affected and be critically ill.

Pang also gave an example during the daily media briefing that in a family with four generations in Beijing, seven family members lived together and three relatives from other places went to visit the family in the middle of January, arriving via Wuhan, epicenter of the outbreak.

Nine people out of 10 in the family appeared to have symptoms of the novel coronavirus successively on Jan 23. The family members didn't have close contact with neighbors or coworkers after being infected, Pang said.

For protection, reporting information about family visits from other places to neighborhood committees is important, said Pang, also advising residents in the capital live separately from their visitors.

Daily body temperature checks should also be conducted for the families if visitors come, and relevant monitoring as well as protection measures should be adopted, Pang added.

By the end of Thursday, Beijing had confirmed 372 cases with three deaths, one died of other illness and 79 cured, according to the city's health commission. Another 289 patients are under quarantine for medical treatment at designated local hospitals.