Earlier Friday, officials had said reported that one person was killed and 18 trapped in the disaster.
According to The City Paper Bogota, four men and four women were detained in Bogota and the central city of El Espinal.
Authorities say they believe Friday's explosion at the mine in the town of Cucunuba was triggered by an accumulation of methane gas.
"The interdisciplinary team continues with the investigation to clarify the different terrorist actions and individualize and identify both the material and intellectual perpetrators of these acts", Nieto said. The suspects are being held in suspicion of conspiracy, terrorism, homicide, kidnapping and aggravated robbery, Colombia's National Police said.
The country's President, Juan Manuel Santos, has expressed his solidarity with the victims as loved ones wait anxiously for news of those caught up in the explosion.
"The evidence indicates that the four men and four women are members of the Movimiento Revolucionario del Pueblo ( the People's Revolutionary Movement), a group that has claimed responsibility for numerous attacks", police said in a statement.
Colombia, a major world supplier, provided more than 70 percent of U.S. coal imports.