China recorded its biggest daily jump in COVID-19 cases in more than five months on Wednesday, despite four cities in lockdown and ramping up testing.
A total of 115 new cases were reported, most of them near the capital Beijing, but a province in northeast China also saw a rise in new cases, according to official data.
New infections have raised worries about a second wave in the country that has mostly contained the disease. 28 million people are under home quarantine.
Hebei province, that surrounds Beijing, accounted for 90 percent of the cases and has put three cities; Shijiazhuang, Xingtai and Langfang, into lockdown.
Beijing city authorities have also stepped up screening and prevention measures to prevent another cluster from developing there.
Meanwhile, with next month's Lunar New Year holiday approaching, China's state planning agency has said it expects travel during the holiday to be markedly lower than normal.
Many provinces have asked migrant workers to refrain from traveling during the break.