Five people died and seven others were missing following methane explosions at a coal mine in southern Poland in the early hours of Wednesday, a senior government official said.

The blasts took place at 12:15 a.m. local time (10:15 p.m. GMT Tuesday) about 1,000 meters (3,000 feet) under the surface at the Pniowek mine in Pawlowice that is operated by the Jastrzebska Spolka Weglowa, or JSW, mining company.

The company said earlier that 21 people had been injured and also spoke of two explosions. There were 42 miners in the area where the explosion happened and many of them suffered burns.

The immediate rescue operation by 13 units of rescuers had to be suspended because of a fire and the need to protect the rescuers, JSW officials said.

"One of the miners injured by the methane explosion at the Pniowek mine has died in hospital," JSW said on Twitter. "That is the fourth victim of today's mining disaster."

Contact with seven of the rescuers has been lost during the operation, mine authorities said.

Prime Minister Mateusz Morawiecki said he would visit the site of the "tragic occurrence," and that the rescue operation was extremely difficult.

Doctors at the Siemianowice Slaskie hospital, which specializes in treating burns, say the condition of some of the injured is life-threatening. They have suffered burns to their lungs and to large areas of their bodies.

Poland relies on its own and imported coal for almost 70% of its energy, drawing criticism from the European Union and environmental organizations concerned about carbon dioxide emissions and climate change. Most coal mines are located in the southern Silesia region.

The government recently announced it will end coal imports from Russia by May, in a drive to wean off dependence on Russian energy sources, but also in direct reaction to Moscow's invasion of Poland's neighbor, Ukraine.