US coal producers are seeking to boost exports to cash in on soaring prices since Russia's invasion of Ukraine but face big headwinds including shipping bottlenecks, labor shortages, and a dismal long-term outlook discouraging investments in new mines.

Data from the National Bureau of Statistics showed the country's raw coal output rose 10.3 percent year-on-year to 1.08 billion metric tons in the first quarter.

The Indian government said on Tuesday that the country's coal production increased 29 percent year-on-year to 66.58 Million Ton (MT) in April amid a power shortage due to lesser stocks of coal available at thermal power plants.

The cancellation of trains includes 500 trips of express trains and 580 trips of passenger trains.

In north China's Inner Mongolia Autonomous Region, the rugged surface of an exhausted coal mine has received a major face-lift, newly populated by 1.12 million photovoltaic modules, beneath which numerous plants are flourishing.

China's central bank on Wednesday announced that it has increased the targeted re-lending quota for the coal industry by another 100 billion yuan (about 15.11 billion U.S. dollars) to support the clean and efficient use of coal.

Mongolia exported a total of 3.8 million tons of coal in the first four months of this year, down 48 percent year on year, Mongolian Customs General Administration said on Monday.

India has eased environment approvals for coal mine expansions to boost output amid fuel shortages that have triggered hours-long blackouts.