People wearing masks walk in front of the gate of the Peking University People's Hospital in Beijing on Monday. Photo: Li Hao/GT

A slew of domestic e-commerce platforms on Wednesday forbade the raising of health-product prices during the pneumonia outbreak in China.

The latest figures from the National Health Commission of China showed the country has thus far confirmed a total of 440 cases of the new form of coronavirus pneumonia. Nine patients have died.

Due to a tightening mask supply amid a continuous stream of new coronavirus cases, some online sellers have purposefully increased their retail prices of face masks. N95 surgical masks could be seen priced from 99 yuan ($14.32) per box to around 400 yuan per box in the past few days, and some retailers have even driven prices up to nearly 1,000 yuan.

Taobao, owned by Alibaba and one of the largest e-commerce platforms in China, said in a statement late on Tuesday that it has issued a notice to all vendors selling face masks, forbidding them from raising prices. "Currently, Taobao's Tmall platform has sufficient stock and Taobao has launched special subsidies for masks in a bid to guarantee consumers are able to purchase high-quality masks at a favorable price," read the statement.

E-commerce giant Suning also announced on Wednesday that it has issued a notice stating that thousands of health products on its platform - sold in online stores operated by its own channel and other vendors - cannot be sold at increased prices. 

The two e-commerce platforms both stressed that their delivery services will operate normally during the upcoming Spring Festival holidays, which start from Friday.

Chinese e-commerce platform Pinduoduo said it will monitor the prices of face masks, disinfectant and thermometers. It will intervene in any attempt to hike prices.

East China's Zhejiang Province and South China's Guangdong Province have stated that they will severely crack down on attempts to push up prices during the epidemic.

Netizens have said that attempts to profit from the disease are immoral, and that such behavior is "disgusting."

Shares of face-mask firms surged at Wednesday's opening. Allmed Medical Products, Jiangsu Jiangnan High Polymer Fiber and Zhende Medical all hit the daily ceiling of a 10 percent rise.