NANCHANG (XINHUA) - Though many factories across China remain empty amid mass quarantine campaign to curb the novel coronavirus spreading, companies that produce masks are going all out to churn out much-needed supplies.

The latest figure shows the novel coronavirus has killed more than 250 and infected more than 11,000 people.

China produces around 50 per cent of the world's masks. However, the current outbreak has increased public demand and put great pressure on production.

"Everybody is wearing masks, from medical staff to ordinary people, and the masks are disposed of every day, so the demand for masks has exploded, causing the temporary shortage," said Mr Li Lingshen, head of China Nonwoven and Industrial Textiles Association.

Manufacturing facilities for masks, protective wear, screening facilities and other medical supplies are going full throttle.

Jinxian county in east China's Jiangxi province is home to 136 companies specialising in medical equipment production. More than 60,000 people are involved in the production and sales of medical equipment. By Thursday, all 30 companies that have mask production credentials had resumed production.

"The government is providing the maximum level of support in the purchase of raw materials and subsidies," said Mr Chen Jian, who heads the county department of science, industry, and information technology.

The county government has forked out 3.5 million yuan (S$690,000) to help companies buy materials. Some companies pay as much as 600 yuan extra to each worker every day.

China's Ministry of Industry and Information Technology said the country produces eight million masks every day. As more companies resume production, the shortage is expected to ease.

Overseas purchases are also arriving. On Thursday, 149,000 masks were sent via air from Vietnam to Lanzhou, capital of north-west China's Gansu province.

Overseas Chinese have donated over one million masks, said Mr Wu Nanxiang, head of Fujian provincial department of commerce.