A new Covid-19 outbreak has spurred parts of China to increase restrictions on movement, with the capital Beijing sealing off some areas and northwestern regions imposing a range of transport curbs and closing public venues.
China, where the coronavirus was first identified in late 2019, reported 28 new domestically transmitted cases for Thursday, more than double the 13 cases a day earlier, health authority data showed on Friday.
The numbers are tiny compared to elsewhere in the world, but Chinese cities are quick to contain outbreaks under tough national guidelines of zero tolerance.
The Changping district of Beijing banned people in certain higher-risk areas from leaving their residential compounds, suspended face-to-face classes at schools close to those areas and ordered nearby businesses to halt operations, an official told a news briefing.
Six local cases, some of the highly transmissible Delta variant, were detected this week in Beijing city, which has vowed high vigilance ahead of the 2022 Winter Olympics Games in February.
Beijing city has started injecting booster vaccine doses, with groups including people taking part in the Games given priority.
In Hebei province next to Beijing, the cities of Xingtai and Baoding, a few hours' drive from Zhangjiakou that is co-hosting the Games with Beijing, this week found a total of four local asymptomatic infections, which China counts separately as confirmed cases.
The majority of the 70 local confirmed cases reported since 16 October were from northwestern China - Gansu province, Ningxia autonomous region and some northwestern areas of Inner Mongolia, which in general are remote and do not have as much health resources as major cities.
Around a dozen cities in Gansu province, many of which have yet to report any local infections, halted some long-distance bus services as of Friday morning, state television said.
A few trains linking Gansu's capital, Lanzhou, and the outside had been halted, while only one flight from Lanzhou to Beijing was allowed, an official said on Thursday.
In Qinghai province, an airport has halted serving passengers transferring flights. The province reported one local case on Thursday, the first this year.
All tourist attractions in Ningxia, and some in Gansu and Qinghai, have been suspended.
Travellers arriving from overseas who have stayed in China for less than 28 days have to take tests before they are allowed enter to Ningxia, and are required to stay indoors for a week of health monitoring on arrival.
China's railway authorities have halted the loading of cargo destined for some stations in the Xijiang region until the end of October, citing virus control measures without giving further details.
Xinjiang reported one local confirmed case and five asymptomatic infections earlier this month. It has reported no infections since 16 October.
As of Thursday, China has had a total 96,665 confirmed coronavirus cases. The death toll stood at 4,636.