At least 35 coal miners have been killed in an accident in northern Iran, with dozens still trapped below the surface.

A large explosion damaged the Zemestanyurt mine, near the town of Azadshahr in Golestan Province, on Wednesday.

Labor Minister Ali Rabiei confirmed early Thursday, “Unfortunately, all miners trapped in the wreckage lost their lives.”

Shahin Fathi, head of the Iran Red Crescent Search and Rescue Unit, said more than 40 miners had been trapped. As oxygen was injected into the mine to increase chances of survival, six of them were rescued with injuries.

The remaining miners were stuck at the far end of a 1,000-meter shaft in a the 2-km (1.25-mile) mine

“Some 600 metres (yards) of the tunnel has been cleared” in the mine, said Reza Bahrami, a mining industry official in Golestan.

A day of mourning has been declared in the province and the Rouhani Government sent two ministers to the scene.

In the midst of campaigning for Iran’s Presidential election on May 19, President Hassan Rouhani said all possible support would be given to the stricken area and those affected by the explosion.

More than 500 miners work in the Azadshahr complex.

TOP PHOTO: People gather at the site of Wednesday’s mine explosion