Residents of the Chinese city of Beijing have been buying up food and supplies ahead of a feared coronavirus lockdown.
The city's largest district of Chaoyang on Monday began mass-testing residents for COVID-19, triggering fears of a repeat of the Shanghai lockdown. Residents will have to go through three rounds of testing at two-day intervals.
From Tuesday to Saturday, the mass-testing regime will be expanded to 10 other districts, local officials said.
Beijing authorities warned that the virus had "stealthily" spread in the city for about a week before it was detected.
For weeks, the 25 million residents of Shanghai have been locked down, with food supply bottlenecks causing widespread discontent.
Beijing supermarkets have massively increased inventories in the face of panic buying, while online delivery stores have boosted stocks and staff.
China has acknowledged 70 detected cases of COVID-19 among eight of the city's 16 districts.
With fears of a lockdown in Beijing, China stocks have slumped to two-year lows. The South China Morning Post reported that Apple supplier Foxconn had suspended production at two of its China factories.