Bogota, Mar 17 (IANS): The death toll from a coal mine blast earlier this week in Colombia's Cundinamarca has increased to 21 after the bodies of 10 trapped miners were found, President Gustavo Petro announced.

"I have just been informed by the Governor ... that despite all rescue efforts, unfortunately 21 people lost their lives in this tragic accident in Sutatausa," Xinhua news agency quoted the President as saying on Thursday.

"Labour and business restructuring plans in coal mining areas have become increasingly essential. Each worker death is not only a business failure, but also a social and governmental failure," he added.

Cundinamarca Governor Nicolas Garcia said the rescuers had sighted the 10 bodies and had begun the extraction process.

He said families of the victims will have the full support of the government with social and psychological services, as well as economic aid.

Eight of the nine miners who survived the explosion were treated in hospital and later discharged, while the ninth remained under observation, according to Cundinamarca fire captain Alvaro Farfan.

Farfan said the National Mining Agency will begin an investigation to determine the cause of the blast in the interconnected mines belonging to the Minminer company, which have been in operation for 30 years.

The National Mining Agency said it has ordered the suspension of Minminer's activities, and initiated an evaluation of the state of the mines after the explosion.