The reports said the deaths happened at a coal mine in Tabas, about 540 km (335 miles) southeast of the capital, Tehran

Authorities were sending emergency personnel to the area after the blast late Saturday, it said

Around 70 people had been working there at the time of the explosion at the site

State television later said that 18 were believed to be trapped inside in tunnels at a depth of 700 metres (2,300 feet) below the surface

Iran's new reformist President Masoud Pezeshkian, preparing to travel to New York for the UN General Assembly, said that he ordered all efforts be made to rescue those trapped and aid their families

He also said an investigation into the explosion had begun

Oil-producing Iran is also rich in a variety of minerals. Iran annually consumes around 3.5 million tons of coal, but only extracts about 1.8 million tons from its mines per year

Iran's mining industry has been struck by disaster before. In 2013, 11 workers were killed in two separate mining incidents. In 2009, 20 workers were killed in several incidents. In 2017, a coal mine explosion killed at least 42 people