The Omicron coronavirus variant has appeared for the first time in China, according to health authorities, piling pressure on officials already contending with an outbreak in one of the country’s most important manufacturing hubs.

Officials and state media said the Omicron case was “imported” by an arrival in the port city of Tianjin, south-east of Beijing, where travellers are quarantined before they are allowed to continue on to the Chinese capital.

“Those infected in Tianjin are currently being treated in isolation in designated hospitals,” the citys local government said on Tuesday. “This is the first time an Omicron variant case has been discovered in mainland China.”

President Xi Jinping’s administration is pursuing a “zero Covid” policy across the world’s most populous nation, in part because of concerns about the relatively low efficacy of China’s homemade vaccines and the potential death toll if Covid-19 spread freely among the country’s 1.4bn people.

China has reported only about 100,000 confirmed Covid cases since the virus emerged in Wuhan almost two years ago — less than the number of daily cases in the US and UK.

The discovery of Omicron in Tianjin came as tens of thousands of people in China have been subjected to new lockdowns owing to Covid-19 outbreaks. Authorities are rushing to contain dozens of cases in the Yangtze river delta, a vital manufacturing centre.

The cities of Hangzhou, Shaoxing and Ningbo — all in Zhejiang province, south of Shanghai — have reported almost 200 new cases this week, prompting authorities to impose restrictions on movement until March 2022.

There were more than 100 infections in one district alone — Shangyu, in Shaoxing — all of which were traced to a funeral, state media reported.

Recommended Many manufacturers have suspended production in the region. Ningbo is one of China’s largest container ports, raising the spectre of further global supply chain bottlenecks.

Xia Yanhong, who runs textile factories in to strict operational controls.

“We have products worth at least Rmb120m [$19m] waiting to be sent out,” said Xia, whose customers are mainly European. “If they cannot be shipped soon, it will have a big impact on us.”