BEIJING - China's coal imports rose in April, customs data showed on Thursday, fuelled by lower domestic production and greater buying by power generators to swell stockpiles ahead of the peak summer demand season.

Shipments of coal into the world's largest consumer of the fuel were 45.25-million metric tons last month, up 11% from 40.68-million a year earlier, the data from the General Administration of Customs showed.

That was up by 9.4% from March and two-million tons less than December's record of 47.3-million tons.

The boost in imports is partly because domestic coal production has not increased to meet demand, said Feng Dongbin, an analyst with consulting firm Fenwei.

China's coal output fell 4% on the year during the first quarter, the most recent data shows, in part because of a string of deadly accidents that forced mines in the top coal-producing province of Shanxi to halt operations for safety inspections.

Domestic demand has also started to pick up because of seasonal factors, the China Coal Transportation and Distribution Association (CCTD), said on Wednesday.

"We have entered a stocking period ahead of the summer peak," said CCTD analyst Xu Dongkun.

The Northern Hemisphere summer months are typically a high demand period for power generation in China as they spur greater use of air-conditioning.

Chinese imports of coking coal for the steel industry were also probably higher because of tighter domestic supply of the fuel, said a China-based trader who sought anonymity as he was not authorised to speak to the media.

Shanxi, the northern province affected by the safety inspections, is a major hub for the production of coking coal.

China's coal imports in the first four months of 2024 were 161.15-million tons, up 13% on the year, the data showed.

China's main coal suppliers are Indonesia, Russia, Mongolia and Australia.