China is also battling a rise in cases in Zhengzhou in northern Henan province, which saw devastating floods just last month, as well as Hainan island.
The Global Times newspaper has called the outbreak the "most serious since Wuhan", and in a separate editorial criticised "glaring loopholes" in Covid prevention measures.
"It is absolutely worrying if a single flaw can affect many provinces and regions across the country... it shows that our systematic progress in fighting the epidemic needs to be strengthened," it said.
The outbreak has raised concerns about vaccines, as it emerged that some of those infected had been vaccinated.
Shao Yiming, a researcher with China's Centre for Disease Control and Prevention, told reporters on Saturday that breakthrough infections in vaccinated people "are expected".
Sinovac and Sinopharm's vaccines - two of the most commonly used jabs in China - have been shown to be 50 per cent to 79 per cent effective in preventing symptomatic Covid infection in clinical trials around the world, but are highly effective in preventing hospitalisations or deaths.