People are snapping up face masks to protect against pneumonia linked to a new coronavirus, triggering tight supplies in large areas of China.

The surge in demand has hollowed out face mask inventories of some vendors on e-commerce platforms, including Taobao and JD.

The online store of 3M shows that several varieties of its regular face masks had sold out as of Tuesday morning. More expensive face masks and gel hand wash are still available.

Dingdang Medicine Express, a popular app featuring rapid delivery of medicines to users' doorsteps, has also reported a sales spike in face masks. Total sales on Monday more than doubled that of the previous week, news website Jiemian.com reported.

Owners of brick-and-mortar pharmacies or convenience stores in cities have also complained about difficulties ensuring sufficient supplies of face masks.

In Wuhan, Hubei province, where the virus first appeared, several pharmacies visited by China Daily on Tuesday reported diminishing stockpiles of face masks, with only a few large-scale drugstores capable of providing surgical masks.

"We have sold more than 200 face masks since Monday. The current stock is empty," said a drugstore staff member in Wuhan on Tuesday. "We are not sure if new supplies will arrive tomorrow."

Allmed Medical, a pharmaceutical company based in Yichang, Hubei province, said on Monday that orders of face masks have increased markedly, and the company is actively ramping up production to ensure supplies in the market, particularly in medical institutions.

The company 3M also said on Tuesday that it has mobilized staff to produce more face masks and will maintain production during the Spring Festival holiday.

Zhang Yan, a saleswoman at a chain drugstore in Shanghai, said many branch stores have requested more face mask supplies but received no replies from the headquarters that manages product distribution.

The city has so far confirmed six cases linked to the new coronavirus.

The Shanghai Market Supervision Administration said in a notice released on Tuesday that sellers should refrain from increasing prices of face masks and other hygiene products, which could disrupt normal market order.

Zhong Nanshan, leader of a high-level expert team investigating the pneumonia outbreak, said on Monday evening that it is important to wear a face mask as a preventive measure.

"Regular surgical masks can prevent most viruses traveling on droplets from entering respiratory systems," he said, adding that people do not have to stick to the N95 mask that can prevent a wider range of tiny particles.