Bogota, Colombia (CNN) -- A coal mine explosion early Thursday in northwest Colombia has trapped 72 miners and killed at least eight workers, President Alvaro Uribe said.
Eight bodies had been retrieved by Thursday morning, Uribe said.
"This is very sad news," Uribe said on the president's website. "The information I have from the minister (of mines) is that they have retrieved eight bodies. This is very grave. And I give this news to Colombians with much pain".
The explosion at the San Fernando mine in the city of Amaga was caused by an accumulation of gas, said John Fredy Rendon, director of the Antioquia Disaster Prevention and Attention System, commonly called DAPARD.
The incident occurred around 1 a.m. local time (2 a.m. ET), during a shift change, which means there were more employees in the mine at the time, Rendon said.
