Authorities in Beijing have raised the city's Covid-19 alert to the second-highest level as a new outbreak continues to spread, further hitting travel demand.
Beijing updated its emergency status to level two last night after reporting another 31 coronavirus cases yesterday, taking the total to 137 since the outbreak started at a food market last week.
Schools have been closed and offices have told staff to work from home. Some outbound bus lines were suspended from this morning, although highways remain open.
But travel within the city has already fallen. People in the 27 medium-risk and one high-risk areas of Beijing have been banned from travelling, while others must prove they are not infected before leaving the city.
More cities and provinces elsewhere in China have imposed restrictions on arrivals from Beijing, including compulsory 14-day quarantines. Covid-19 cases linked to the Beijing outbreak have been found in provinces including Zhejiang, Liaoning, Hebei and Sichuan.
The travel curbs have hit flight activity. There were 715 departures and arrivals from Beijing airports yesterday, down by 35pc from a week earlier, with about 37pc of scheduled flights cancelled. Around 52pc of today's scheduled flights were cancelled as of 3pm Beijing time (7am GMT), according to Chinese flight data company Variflight.
The heightened alert in Beijing comes just 10 days after the city downgraded its coronavirus assessment. The city had previously gone almost two months without any local transmission of the virus.

