China has recorded the biggest daily jump in Covid cases in more than five months, despite four cities in lockdown, increased testing and other measures aimed at preventing another wave of infections in the world's second-largest economy.
Most of the new patients were reported near the capital Beijing, but a province in northeast China also saw a rise in new cases, official data shows, amid a resurgence that has seen more than 28 million people under home quarantine.
The National Health Commission said 115 new confirmed cases were reported in the mainland compared with 55 a day earlier.
This was the highest daily increase since July 30.
The commission said 107 of the new cases were local infections. Hebei, the province that surrounds Beijing, accounted for 90 of the cases, while northeastern Heilongjiang province reported 16 new cases.
Hebei has put three cities - Shijiazhuang, Xingtai and Langfang - into lockdown as part of the efforts to keep the virus from spreading further,
Beijing city authorities have stepped up screening and prevention measures to prevent another cluster from developing there.
Heilongjiang province on Wednesday declared a Covid-19 emergency.
The city of Suihua, which borders the provincial capital Harbin, put its 5.2 million people under lockdown.
Most of the cases in Heilongjiang have been found in Wangkui county, under Suihua's jurisdiction, which had already been put into a lockdown earlier this week.
The number of new asymptomatic cases, which China does not classify as confirmed cases, fell to 38 from 81 cases a day earlier. Seven of those were reported in Jilin, another northeastern province that borders Heilongjiang, underscoring the risk of transmission into different parts of the country.
The total number of confirmed Covid-19 cases in mainland China now stands at 87,706, while the death toll remains unchanged at 4634.
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