Ukraine ? A methane blast ripped through a coal mine in eastern Ukraine early Sunday, killing at least 65 miners in the ex-Soviet nation’s worst mining accident in years, emergency officials said.

More than 360 miners were rescued but 35 others remained trapped inside the mine – one of Ukraine’s largest and deepest – with a raging fire hampering efforts to save them, officials said.

The explosion occurred around 3 a.m. more than 3,300 feet deep inside the Zasyadko mine in the regional capital Donetsk, the heart of the country’s coal mining industry, the Emergency Situations Ministry said.

Ukraine has some of the world’s most dangerous mines.

Local authorities declared three days of mourning for the dead miners.