A powerful explosion in a coal mine in central Colombia that affected four other mines linked by tunnels has killed at least 11 people and left others missing, the government said Wednesday.

President Gustavo Petro said on his Twitter account that rescuers were making every effort to reach the trapped miners.

The blast took place Tuesday night in the municipality of Sutatausa in Cundinamarca province.

Cundinamarca Gov. Nicolás García Bustos initially reported four deaths with two people recovered alive and 17 still trapped in the mine.

Álvaro Farfán, captain of the Cundinamarca fire department, told local media the explosion affected five mines interconnected by tunnels, generating a “chain" blast.

Petro later raised the death toll to 11, but did not say how many miners were still trapped.

Farfán said the initial hypothesis is that the explosion was caused by an accumulation of gases.

Explosions, landslide and other emergencies are common in Colombian coal mines.