Authorities in Guangzhou, which has a population of around 15 million, reported 20 new infections over the past week, a relatively small figure compared to other countries’ current rates but enough to alarm Chinese officials who believed they had the virus under control.
The spread of the virus has been “fast and strong”, with infections growing more rapidly in Guangzhou than in previous outbreaks, China's state-owned Global Times quoted a health official as saying. Nearly half of the cases are thought to be linked to one woman infected with the Indian variant.
Residents in Liwan district, a cluster of five streets in the city centre, have been ordered to stay at home, Guangzhou officials said in a statement.
Outdoor markets, child care centers and entertainment venues were closed. Indoor restaurant dining was prohibited. People in parts of four nearby districts were ordered to limit outdoor activity.
The Guangzhou government has ordered testing of hundreds of thousands of residents following the initial infections. Officials are conducting door-to-door tests and said some 361,421 people had been tested since Wednesday.
China reports a handful of new cases every day but says almost all are believed to be people who were infected abroad. On Saturday the National Health Commission reported 16 new cases, 14 of which it said were imported.
Two new cases in Guangzhou were reported as locally transmitted. City officials said nine of the recent infections were believed to be linked to a 75-year-old woman who was found to have been infected with the Indian variant on 21 May.
The official death toll for the Chinese mainland stands at 4,636, with 91,061 confirmed cases. Guangdong province, where Guangzhou is situated, has reported a total of 2,427 cases.
Additional reporting by agencies