An Associated Press report said rescuers recovered the bodies of 16 miners who died from carbon monoxide poisoning on Wednesday afternoon. Three others died on their way to hospital.

According to state news agency Xinhua, 154 miners were working underground at the time of the explosion. Twenty-eight are still trapped.

The mine is owned by Zhengjin Industry and Trade Company in Panzhihua, 750km southwest of the provincial capital of Chengdu.

The mine’s owner is under police custody.

The news follows local media reports of an unspecified accident at the city of Changji's Hongxing coal mine where six miners were killed and six more injured Tuesday.

On Monday, a 10m of roof collapsed at the Nuanquan operation in Shanxi province where efforts to rescue seven trapped miners are ongoing.

The string of incidents has sharpened government focus on the dangerous nature of China’s small coal mines.

The State Administration of Work Safety said last week it planned to reduce the number of fatalities by closing more than 600 small mines.