Deliveryman passes a package to a resident through locked gate in Beijing on February 5. Photo: Li Hao/GT

A central Beijing hospital reported 36 novel coronavirus cases as of Thursday, a sharp increase from nine cases from two weeks earlier, leading many to fear a potential explosion of infection numbers in the capital.Among the infected at Fuxing Hospital in Xicheng district were eight medical workers, nine cleaning staff and 19 patients along with their families, the Beijing government's leading group for COVID-19 prevention and control work said at a press conference on Thursday."Considering 36 confirmed cases were found in Fuxing Hospital, it is more about one case of multiple infections rather than an epidemic of the whole area," Wang Guangfa, director of the department of respiratory and critical care medicine at Peking University First Hospital, told the Global Times on Thursday.Another major hospital, Peking University People's Hospital, on Thursday for the first time reported confirmed cases of infection. Three patients at the hospital were confirmed to have the novel coronavirus on February 17 and were sent to designated medical institutions for treatment, authorities at the press conference said.A total of 164 people including medical staff at Peo-ple's Hospital who have had close contact with the patients have been put under close medical observation. The hospital also conducted coronavirus tests on 251 personnel and nine environments, and the results were all negative. The hospital has sterilized places that the patients may have touched, and hemodialysis rooms were sterilized when each shift was completed.The three patients are from one family. Tian, a patient in the geriatrics department, had been hospitalized for six months for a kidney illness and had to undergo hemodialysis regularly. After her daughter and son-in-law came back from Xinjiang , they visited Tian separately. The couple became infected on February 17.Among the 668 people who had close contact with infected patients in Fuxing Hospital, 582 have been removed from medical observation as of Thursday, and the building where the infections occurred has also had its blockade lifted.The infection cases at the two hospitals pushed the confirmed cases in the central Xicheng district to 53, ranking third among all districts. As of Wednesday night, Beijing had confirmed 395 cases of novel coronavirus infection, with four deaths. In total, 153 cases have been discharged from hospitals. A total of 2,091 people are listed as having had close contact with infected patients.According to a table which compares the "infection density" of cities or areas — the number of confirmed cases per square kilometer —Xicheng district ranks second, with an infection density just lower than the epicenter Wuhan.Xicheng district lies at the center of Beijing and had a permanent resident population of about 1.14 million by the end of 2019. Beijing has a permanent resident population of over 20 million.The municipal government's leading group said that all hospitals in Beijing should accelerate hospitalization of patients and try their best to diagnose suspected cases to treat the infected patients at the earliest time.The infections are scattered around 15 of Beijing's 16 districts, with Pinggu district so far unaffected.Though it may look serious, Wang believes the so-called infection density does not describe the whole picture about the epidemic in Xicheng district.More efforts should be made to further search for and isolate the close contacts so as to stop the epidemic from further expanding, Wang warned. "We should be vigilant against the clusters of infections happening in hospitals, as medical workers fighting at the frontline and patients are vulnerable to any additional disease."To hold back the virus, Beijing enacted a law recently that said all people coming to the capital must be quarantined for 14 days. Violators will be punished by law. Authorities fear an influx of migrant workers returning to Beijing could pose potential dangers of wider infection for the city.