Another 24 miners are believed to be trapped inside after the explosion struck a mine in Tabas, some 335 miles southeast of the capital, Tehran.

The state-run IRNA news agency said authorities had sent emergency personnel to the area.

Around 70 people had been working there at the time of the blast, which happened late Saturday.

It is not clear if any remain trapped inside.

Iran's new president Masoud Pezeshkian, preparing to travel to New York for the United Nations General Assembly, said he ordered all efforts be made to rescue those trapped and aid their families.

He also said an investigation into the incident had begun.

This is not the first disaster to strike Iran's mining industry.

Read more:
Trump vows to reach Mars if elected
Fire rips through missile depot deep inside Russia
Pilot held hostage arrives in Jakarta

In 2017, a coal mine explosion killed at least 42 people, while 11 workers were killed in two separate mining incidents in 2013.

Lax safety standards and inadequate emergency services in mining areas are often blamed for the fatalities.

Iran annually consumes some 3.5 million tons of coal but only extracts about 1.8 million tons from its mines per year. The rest is imported, often consumed in the country's steel mills.