Local officials in Beijing said the number of coronavirus cases in the capital is increasing. They said while the majority of cases involve people who have come from outside the city, these cases are now causing the overall number to rise. Officials added that they have noticed a trend towards clusters of cases, or multiple cases in the same general area, which can increase the spread of the virus within the city. Elderly and people with underlying diseases are especially vulnerable. They added that the number of second-generation cases (residents who have been infected by people from Hubei Province or its capital Wuhan) in Beijing has also increased. Officials said this kind of contamination spread is hampering the containment efforts in the Chinese capital.