At least two miners have been killed and as many as 50 are trapped after a large explosion in northern Iran.
A local official said the tunnels were filled with gas, making rescue work hard.
The blast occurred at 12:45 p.m. local time (0745 GMT) in the Zemestanyurt coal mine in Golestan.
The explosion is understood to have taken place as workers were changing their shifts at the mine. He said as many as 80 miners could be trapped in two sections of the mine.
Another miner said he feared his colleagues trapped inside may have died.
Press TV posted several photos of people gathered at what appeared to be a mine entrance, and emergency workers caring for those injured.
Golestan runs along Iran's northern border with Turkmenistan.
Iran extracts about 1 million tons of coal from its mines each year, using most of it in its steel mills, the AP reported. Lax safety standards and inadequate emergency services in mining areas often are blamed for the fatalities.
Iran has started to renovate some of its coal mines since making a nuclear deal with world powers, but has not completed all the renovations, the AP reported.