Pharmacies in Beijing and Shanghai were running low on surgical masks and disinfectants Wednesday as a deadly new SARS-like virus spread ahead of the busy Lunar New Year travel period.

More people than usual were seen wearing masks on the streets and several stores AFP visited had run out of stock -- to the dismay of customers.

The rush to step up protective measures against the new coronavirus came after it infected more than 400 people across China.

The illness, first discovered in the central city of Wuhan, is spreading just as hundreds of millions of people take to packed trains, planes and buses around the country on their way to reunions with family and friends for the festive period.

An employee at a pharmacy in Beijing told AFP it had run out of surgical masks two days ago.

"When it hit close to 300 cases, people realised it was serious," he said, adding that items such as thermometers had also been selling fast.

"It happened so suddenly; we didn't prepare any back-up and existing stock was quickly depleted."

A batch of masks that arrived on Wednesday morning sold out in just half an hour, he added.

The store still had other masks in stock but these were not designed for surgical purposes.

At another pharmacy in Beijing, a sign on the door said they were also all out of the products.

"We get some stock every day, but it is not enough to fulfil demand," said a staff member who did not want to be identified.

"We have also run out of disinfectants," she said. "We are working hard to replenish stock but we don't know when it will come."

Beijing's Market Supervision and Regulation Bureau issued a statement on its WeChat account Wednesday with guidelines for businesses, to help "ensure the stability of prices for goods such as masks and other items related to the epidemic".

In Shanghai, supermarket staff continually restocked shelves as shoppers snapped up the available products.

Some hospitals and clinics in the financial hub set up stations at the entrances to their emergency units to screen people with flu symptoms.

The coronavirus has caused concern due to its genetic similarities with Severe Acute Respiratory Syndrome (SARS), which killed nearly 650 people across mainland China and Hong Kong in 2002-2003.

But not everyone is nervous.

"The situation doesn't seem as serious as in 2003 during the SARS outbreak. Having experienced that outbreak, people are less panicky," said a 40-year-old woman surnamed Zhou in Beijing.

"We know how to protect ourselves and ventilate our homes. It's close to the Spring Festival too, and we have to go house-visiting. If relatives are worried, we will wear masks in their houses."

Wang Suping, 50, who works at an arts school, said: "These days, I wear masks even in places that are not too crowded although I wouldn't have done so in the past."

She was not anxious as she had medicine and masks at home, she added.

"When you can't contain the virus, we have to do what we can to protect ourselves."

Coronavirus China Medicine