A surge in coronavirus cases in South Korea — many traced to a church — provoked fresh alarm Friday, after Chinese authorities reported hundreds of new infections at prisons, undercutting Beijing’s effort to show progress in containing the deadly epidemic. South Korea’s cases skyrocketed to 204, prompting officials to ramp up control measures, as worries mounted that the country is becoming a new hot spot for infection.

Earlier, a handful of Chinese prisons reported nearly 500 new cases, a significant portion of the more than 1,100 new cases reported in mainland China on Friday — and a marked increase after several days of declines. Tests at a prison in eastern Shandong province showed 207 out of 2,077 inmates and staff were infected, and the provincial justice department’s Communist Party secretary was dismissed as a result, the province announced. Another jail in Zhejiang province found 34 cases. Hubei province, at the center of the outbreak, said Friday it found 220 new cases inside penitentiaries. The prison outbreaks underscored the SARS-CoV-2 virus’s high transmissibility in confined spaces after the disease ravaged the Diamond Princess cruise ship docked in Japan.

China’s government has sought to encourage companies to resume work after an extended Lunar New Year closure aimed at containing the virus, but some factories have been forced to shut down soon after reopening as infections surface.

Here are the latest developments:

● Cases in South Korea soared, with investigators focusing on a church and hospital in the southern city of Daegu as clusters of infection.

● The discovery of hundreds of new coronavirus cases in Chinese prisons underlined fears about the virus’s ability to spread rapidly in confined areas.

● Hundreds of passengers were disembarking from the Diamond Princess cruise ship, but the massive case load left troubling questions about the rigor of quarantine and testing procedures on board.

● Officials in Wuhan have been disinfecting the city’s drainage pipes amid concerns that the virus could spread through the sewer system.