Iran mine tragedy takes more victims after second blast

At least 21 miners have died following a blast at a mine in Iran with colleagues desperately working through the rubble to find survivors from an earlier shaft collapse.

The men were killed when gas filled the tunnels and exploded, as they attempted to reach other miners trapped deeper into the mine.

Those attempting to rescue the men after the blast are being treated for burns and gas poisoning.

Meanwhile, work is still underway to try and reach the 32 miners trapped in a tunnel deeper underground at the Zemestan Yort mine in Golestan province.

Methane gas in the tunnels exploded when they attempted to jump start a locomotive engine

They are trapped at the far end of a shaft 1,300 metres underground with rescue workers trying hard to reach them.

The operation has been set back with tunnels filling with gas, but rescue teams are still making progress.

"Some 600 metres of the tunnel has been cleared" in the mine, Reza Bahrami, a mining industry official in Golestan told AFP.

Authorities are trying to remove monoxide gas in the tunnels before they continue their work.

They were hoping to speed up work as an air-pumping machine had arrived at the site.

President Hassan Rouhani, who is seeking re-election this month, has sent the Minister of Labour and Welfare Ali Rabii to the site to lead the operation.