Authorities say they have detained a retired army general as part of an investigation into the 2001 massacre of at least 26 people in southwestern Colombia.

Interim Attorney General Guillermo Mendoza says Ret. Gen. Francisco Pedraza was captured Wednesday at the installations of the IV Brigade in Medellin, Antioquia. He is being investigated for homicide, forced displacement and terrorism.

The prosecutor's office said in a statement Thursday that Pedraza is suspected of failing to act to stop the killings in Naya, Cauca state.

At the time, Pedraza was commander of the brigade that had jurisdiction over the region in question.

Pedraza could not be reached for comment and it was not immediately clear if he had contracted a lawyer.