BEIJING -- China's value-added industrial output, an important economic indicator, returned to growth in April as factory activities gradually recovered on easing containment measures against the novel coronavirus, official data showed Friday.

The value-added industrial output went up 3.9 percent year-on-year last month, rebounding from the 1.1-percent drop in March and 13.5-percent slump seen in the first two months of the year, according to data from the National Bureau of Statistics (NBS).

The expansion marked the first increase after the novel coronavirus outbreak.

Output by the manufacturing industry reported the quickest recovery by expanding 5 percent year-on-year, with that of high-tech manufacturing and equipment manufacturing rising 10.5 percent and 9.3 percent, respectively.

Output in industries in the production and supply of electricity, thermal power, gas and water reported a year-on-year increase of 0.2 percent, while the mining sector saw output up by 0.3 percent.

In the first four months, industrial output went down 4.9 percent year-on-year, with the rate narrowing 3.5 percentage points from the drop seen in the first quarter.

With consolidated epidemic control efforts and the restoration of economic activities, major indices have sustained the improving momentum since March, the NBS said in a statement.

But with the global spread of the virus, domestic recovery still faces many challenges, it added.

In a breakdown by ownership, output by the private sector went up 7 percent year on year.

The output of State-controlled enterprises edged up 0.5 percent, that of joint-stock companies rose 4 percent, and that of overseas-funded enterprises rose 3.9 percent.

The industrial output is used to measure the activity of designated large enterprises with an annual business turnover of at least 20 million yuan (about $2.82 million).

Friday's data also showed improvements in other readings of economic indicators. Fixed-asset investment declined 10.3 percent in the first four months, with the fall narrowing by 5.8 percentage points compared with the decrease in the first three months.

Retail sales of consumer goods went down 7.5 percent last month, recovering from a drop of 15.8 percent in March.