From Saturday, all passengers on planes, high-speed and other trains, as well as interprovincial buses and ferries will have to show a negative PCR test result from the previous 48 hours. The NHC has also urged people travelling between provinces and regions to “voluntarily” take PCR tests on arrival.

This is a change for interprovincial travel – previously people travelling from a low-risk area were not usually required to show a negative PCR test result. But those taking transport from areas where Covid-19 cases had been found were required to produce negative PCR test results before boarding.

The stricter requirements come as China has seen a surge in cases in recent weeks, with the number of areas with infections at a record high. The authorities continue to stick to a tough zero-Covid policy with millions again under lockdown, even though case numbers are low compared with those in other countries.

“As the Mid-Autumn Festival and National Day holidays are approaching and the flow of crowds increases, the risk of spreading the epidemic is growing,” Wu Liangyou, an official with the NHC, told reporters. “The measures are to ensure that no large-scale outbreaks occur before or after the holidays.”

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In the past few months, Beijing has repeatedly called on authorities across the nation to ensure the party congress runs smoothly and reduce any risks to the political, economic and social stability, including avoiding a spike in Covid-19 cases.

The NHC also said anyone checking in at a guest house or hotel or entering a tourist attraction would have to show a negative PCR test result from within 72 hours. Construction workers travelling home from other provinces or regions also have to produce a negative result from the previous 48 hours.

The NHC called for large gatherings such as exhibitions and artistic events to be postponed until after October “unless necessary”, without giving further details. It said if the events did go ahead, PCR test results must be shown for entry. Weddings and funerals should be kept simple, with only a small number of people attending.

China has previously used Covid-19 restrictions to discourage people from travelling between provinces and regions during long public holidays, though they have not been barred from doing so.

In July, authorities in Henan province used the phone-based “health code” to control the movements of protesters in Zhengzhou.

They found their codes had turned red – meaning they could not travel – when they tried to protest over a banking scandal that saw thousands of depositors unable to access their funds.

The incident added to fears that Covid-19 controls could be used to restrict movements other than for public health reasons, which the authorities have said would not be allowed.