This included a shipment of over 4.2 million medical masks to China through border gates in the northern province of Lang Son between January 29 and February 3, deputy head of Vietnam Customs Mai Xuan Thanh said at a government meeting Thursday.

He did not mention specific figures for face mask exports in January or for 2019.

In addition to medical masks, the Lang Son Customs Department processed nearly 800,000 masks of other types, including dust-proof, 3-layer, 4-layer and 5-layer masks to China in the above 6-day period, the agency said.

As of Tuesday, another shipment of 150,000 masks was awaiting export clearance in the province’s Huu Nghi border gate, while a total of 1.3 million medical masks were awaiting the completion of similar procedures at the Chi Ma border gate, Lang Son Customs said.

Due to the sudden increase in demand amidst the ongoing novel coronavirus (2019-nCoV) outbreak, there was a shortage of goods such as masks and antiseptics in the local market, and their prices have been inflated, while the antibacterial filter cloth used to make facemasks is mainly imported from China. 

Mask prices have been soaring across the country and drugstores are running out of supply as people seek protection from the nCoV, which has so far recorded 13 confirmed infections in Vietnam.

Mask manufacturers are running at full capacity but are struggling to source feedstock since China has banned exports as it seeks to contain the spread of the deadly virus.

Some mask producers are considering importing from other countries such as India, whose prices are higher than that of China.

As of Saturday the epidemic had killed 724 people, mostly in mainland China, and infected nearly 34,900.