BEIJING -- While battling against the recent flare-ups of COVID-19 in parts of the country, China has been steadily promoting work resumption in the epidemic-affected areas.

With the epidemic situation gradually easing in Shanghai, major enterprises in the eastern Chinese metropolis have resumed stable production, as key industrial chains, such as automobiles, integrated circuits and biomedicine, continued to recover and ramp up production capacity.

All four factories of the US manufacturing company 3M in Shanghai had resumed production by Saturday, the company said, adding that it will continue to improve its production capacity.

Since the resurgence of COVID-19 cases in March in Shanghai, 3M has not suspended its East China Distribution Center and the production of medical protective masks at its Caohejing base to ensure the stable supply of anti-epidemic materials, the company said.

"Now, 3M is gathering the strength of the entire company to actively deploy resources, so as to ensure the closed-loop production of epidemic prevention supplies," said Ding Hongyu, president of 3M China.

On Wednesday, a ship carrying 4,767 electric cars produced by US automaker Tesla's Shanghai Gigafactory left a Shanghai port for Slovenia, according to Shanghai customs.

It marked the first export shipment of Tesla cars from Shanghai since the company resumed production on April 19 after a hiatus of over 20 days amid the epidemic.

The company said its Shanghai factory has already started manufacturing vehicles for export to the Asia-Pacific and European markets.

"We believe that the epidemic situation is only a short test and challenge. We have seen the capacity of all sectors to cope with the challenges in the process of resuming work," said Tao Lin, vice-president of Tesla. "We believe that production will soon return to normal."

According to a press conference held on May 5, over 70 percent of Shanghai's 1,800-plus major enterprises had resumed work and production.

Earlier this year, the southern city of Shenzhen, a tech hub and a major foreign-trade center in China, also saw a resurgence of COVID-19 infections.

The city took a series of measures, such as suspending public transportation and closing some businesses, from March 14 to 20, and successfully brought the epidemic situation under control. Thanks to the effective actions, businesses gradually resumed normal work and operation starting late March.

Sources with the on-demand delivery service provider Lalamove, known as Huolala in Chinese, said the company saw an obvious drop in the number of orders it received in Shenzhen from March 14 to 21.

However, the number of overall orders handled by the company in the city from March 1 to April 20 was almost equal to the same period last year, with 6,037 new drivers from Shenzhen joining the platform during this period.

During the first quarter, the total number of commercial entities in Shenzhen reached more than 3.85 million, with 88,065 newly registered ones. Over 90 percent of the newly-registered commercial entities are from the tertiary industry, according to the local government.

The city's electricity consumption came in at more than 8.3 billion kWh in April, a year-on-year growth of 0.1 percent and month-on-month growth of 8.8 percent, said the Shenzhen branch of the China Southern Power Grid.

The automobile manufacturing industry has been a main driving force for power consumption, showing an increase of 80 percent in April compared to the same period in the previous year. The electricity consumption of information-related services rose 8.5 percent year-on-year in April.

The northeastern province of Jilin, where over 60,000 cases were reported in the latest outbreak, cut off all COVID-19 transmission chains in communities by April 14. The provincial capital Changchun announced on May 1 that it has cleared all medium and high-risk areas for COVID-19.

Leading Chinese automaker FAW Group Co Ltd began work resumption on April 13 after a month-long suspension. Workers in its five main engine plants in Changchun are working in shifts while some production lines are operating at full capacity.

The company's daily output of complete vehicles has exceeded 4,000 units, and the capacity utilization rate of its factories in Changchun has recovered to 75 percent.

Li Risheng, a FAW employee, said many of his colleagues voluntarily gave up their holidays since the work resumption. "Everybody hopes to speed up the production to recover the losses incurred by the epidemic," he said.

All major express delivery firms including China Postal Express & Logistics, JD.com and SF Express, have seen their distribution centers in Changchun resuming work from April 24.