The number of people killed in a coal mine accident in China's Sichuan province on Saturday has climbed to 28 after a severely injured miner died when rescue efforts failed, an official said on Sunday.

Work safety authorities have ordered the suspension of operations in all coal mines in the province while an overhaul takes place.

According to Sichuan Provincial Work Safety Bureau, there was a gas explosion at about 2 pm on Saturday in Taozigou coal mine, in Luxian county in the city of Luzhou, when 108 miners were working underground.

By late Saturday night, 81 people were rescued but one died later in hospital.

According to the hospital affiliated with Luzhou Medical College, where the injured are receiving treatment, most victims suffered burns and fractures. Late last night there were still eight people with severe injuries and 10 with minor injuries in hospital, including three in a critical condition.

"We should draw lessons from the coal mine accident and will launch an investigation into safety levels to ensure people are not at risk of harm at work and to prevent any future similar incidents," said Yang Dongliang, head of the State Administration of Work Safety, on Sunday.

Yang and other officials arrived at the scene for further investigations on Saturday night.

An initial investigation indicated that unauthorized mining was undertaken at the Taozigou coal mine, the administration told a news conference in Luzhou.

The explosion was the result of high gas density due to poor ventilation, said Fu Jianhua, deputy director of the administration.

The administration's director Yang Dongliang said all licenses the coal mine possessed must be revoked and the site will be shut down permanently.

Liu Jie, deputy governor of Sichuan, said the Taozigou coal mine should be shut down "as soon as possible" and production at all coal mines in the province should be suspended for an overhaul.

Meanwhile, the number of casualties needs to be verified and the injured should be treated, Yang said.

He added that a thorough investigation into the cause of the accident should be carried out so that those responsible are dealt with in accordance with the law.

Xinhua contributed to this story.