On Saturday, operator ArcelorMittal Temirtau, the local unit of Luxembourg-based steelmaker ArcelorMittal, said 206 of 252 people at the Kostenko mine had been evacuated after what appeared to be a methane blast.
Gennady Silinsky, a senior emergency services official, on Sunday confirmed the death toll and continuing operation in Karaganda, a major coal mining centre, to Kazakhstan's Khabar-24 television.
"Work is going on round the clock in shifts in two areas of operations," Murat Katpanov, another emergency official, told Khabar-24.
"Gas levels are normal. There are no visible signs of fire."
Earlier statements said rescue operations in the two areas - 4 km (2.5 miles) apart - were hampered by power cuts and wrecked equipment.
