Beijing has locked down several districts after cases of the novel coronavirus unexpectedly spiked from an outbreak that appears to be linked to Asia’s biggest wholesale food market. Reuters reports that several districts in the Chinese capital have set up security checkpoints, closed schools and ordered people to be tested for COVID-19. Beijing officials have reported 79 cases over the past four days—the biggest cluster of infections since February. The outbreak has shocked residents after nearly two months went by with no new infections. “The risk of the epidemic spreading is very high, so we should take resolute and decisive measures,” Xu Hejiang, spokesman for the Beijing city government, said Monday. The outbreak has been traced to the huge Xinfadi market, where thousands of tons of vegetables, fruits, and meats are bought and sold each day.