More than 50 miners are trapped after an explosion in a coal mine in Iran, state media reports say.

It happened at the Zemestan-Yurt mine in Golestan province in the north.

Two people are reported to have died and 25 others are wounded. One emergency services spokesman said that 16 people had managed to escape.

There are some reports that the incident was caused by a gas explosion, possibly as someone was attempting to start a lorry engine.

Pirhossein Koulivand, the head of Iran’s emergency services, told the country’s news agencies that the number of trapped miners may be much higher, with 40 trapped in one section, and a similar number in another.

He said that 12 miners had escaped unhurt, and another four were injured and taken to hospital for treatment.

The rescue operation has reportedly been hampered by concerns about gas in the tunnels.

Hamidreza Montazeri, deputy head of the provincial emergency services, told Iran’s PressTV that 25 people involved in the rescue had been taken for treatment after inhaling gas.

According to state media, the mine employs some 500 workers, and the explosion – which took place at about 12:45 local time (09:45 GMT) – happened during a change of shift.

Iran, which extracted 1.68 million tonnes of coal in 2016, mostly uses the coal it extracts on domestic steel production, rather than exporting it.