Two methane explosions at a coal mine in southern Poland killed five people and injured more than 20 early Wednesday, the Polish prime minister said. Seven others were missing.

Iran PressEurope: Poland has witnessed numerous accidents in its mines in recent years. The country needs coal to supply its fuel consumption.

The first blast took place shortly after midnight about 1,000 meters (3,000 feet) under the surface at the Pniowek mine in Pawlowice, Prime Minister Mateusz Morawiecki told reporters outside the mine’s office building.

Morawiecki said a rescue operation was launched immediately, but a second explosion occurred about three hours after the first, and communication was lost with some of the rescuers.

The operation was suspended due to the resulting fire and dangerous conditions. Experts were evaluating the possibility of resuming the rescue mission.

The mine, close to the Czech border, is operated by the Jastrzebska Spolka Weglowa, or JSW, a mining company. Prosecutors have opened an investigation. 219