Colombia's government is blaming the country's second-largest rebel group for the disappearance of three journalists in a lawless region of the country.

Defense Minister Luis Carlos Villegas said Thursday that intelligence reports confirm that the National Liberation Army is responsible for the journalists' disappearance.

While stopping short of saying the journalists had been taken hostage, he said a more than prudent amount of time had passed since they were last heard from and insisted it is up to the guerrillas to assure their safe return.

Salud Hernandez-Mora, a longtime correspondent for Spanish newspaper El Mundo, went missing over the weekend on assignment in the volatile Catatumbo region. Two other journalists from network RCN went missing Monday later while covering the search for the Spanish journalist.