BEIJING — China plans to shut down more small-scale coal mines due to safety concerns, with a target to cut the number of mines with annual capacities below 300,000 tons to less than 800 by 2021, according to a document released by the top economic planner.

While weeding out mines that do not meet safety and environmental standards, authorities will also support mines that boast rich resources and high safety standards to upgrade their capacities to higher levels, said the document by the National Development and Reform Commission.

To address problems such as over-supplies and poor safety records, China has strictly controlled new capacity in the coal industry in recent years and halted the approval of any new coal mines unless a certain amount of outdated capacity is shut down as required.

The document said authorities will stick to the capacity replacement plan to strategically approve construction of mines of advanced capacities.

Earlier data from the China National Coal Association showed the number of coal mines in China was reduced sharply to 5,800 at the end of 2018, and the average production capacity was raised to about 920,000 tons per year.