Beijing, April 25 : Beijing reported 16 confirmed Covid-19 cases and five asymptomatic cases, according to local disease prevention and control center. The Covid-19 cases were reported between 4 p.m. Saturday and 4 p.m. Sunday, Xinhua news agency reported. A total of 41 infections have been logged since Friday, involving five districts, said Pang Xinghuo, Deputy Head of the Beijing municipal disease prevention and control center. Preliminary epidemiological investigations indicate that the virus has spread for a week, with multiple generations of cases appearing in a short period of time, he added. Nearly a quarter of the 41 cases are aged 60 years or above, half of whom have not been vaccinated, according to Pang. One neighbourhood in the city's Chaoyang district has been classified as a high-risk area, and another as a medium-risk area. Yang Beibei, Deputy Head of Chaoyang district, said 1,230 close contacts have been identified and 14 areas have been placed under closed-off management in the district. District-wide nucleic acid testing will be organised from Monday. Yang added that the district has suspended all offline training sessions and group activities at various off-campus training institutions. /IANS