BEIJING -- China's production of coal, crude oil and natural gas maintained steady expansion in the first half of the year, official data showed.

Miners in the country churned out 390 million tons of coal in June, up 2.5 percent year-on-year. Coal output during the first half of the year reached 2.3 billion tons, 4.4 percent higher than the same period last year, according to the National Bureau of Statistics (NBS).

During the January-June period, the country imported a total of 220 million tons of coal, up 93 percent from a year earlier.

The country's crude oil output climbed 2.1 percent year-on-year during the period to 105.05 million tons while its crude oil imports gained 11.7 percent to 282.08 million tons.

Production of natural gas rose 5.4 percent in the first half of the year to 115.5 billion cubic meters, while that of imports expanded 5.8 percent to 56.63 million cubic meters, according to the NBS data.