Three journalists held by Colombia's Marxist ELN rebels were freed on Friday after going missing over the past six days in the restive Norte de Santander province.

Spanish journalist Salud Hernandez, who went missing on Saturday in El Tarra municipality, was freed in the early afternoon and called into various radio and television stations to confirm her release.

Colombian reporter Diego D'Pablos and cameraman Carlos Melo, who went missing on Tuesday after going to the largely lawless northeastern area to cover Hernandez's disappearance, were freed Friday evening and spoke live to their employer, Noticias RCN.

Hernandez, who had been last seen climbing aboard a motorcycle taxi while reporting a story on the illegal drug trade, thanked the Catholic Church for its help with her release.

"Thank you to the Catholic Church, to all my colleagues," Hernandez said by telephone to Caracol television news. "I'm perfectly fine."

Hernandez said at a press conference that leftist National Liberation Army (ELN) rebels had treated her well and told her they would hold her for several days.

The government confirmed on Thursday that the three journalists were being held by the ELN, which operates in the area alongside larger rebel group the Revolutionary Armed Forces of Colombia, or FARC, and criminal gangs.

In a printed statement given to Hernandez, the ELN said it was responding to what it perceived as a security threat.

The release of the reporters could help move the ELN and the government toward beginning the peace talks they announced in March. The negotiations have been delayed by the rebels' continued kidnappings and infrastructure attacks.

Hernandez, 59, who writes for Spain's El Mundo and local newspapers, is known for opinion columns highly critical of Colombia's insurgents, the administration of President Juan Manuel Santos and its more than three-year-old peace talks with the FARC.

Santos reiterated to reporters Friday afternoon that no official talks would begin until the group frees all hostages.

"We celebrate the liberation of Diego D'Pablos and Carlos Melo. We expect them to reunite with their families," the president said on his Twitter account.

Norte de Santander is a hub for cultivation of coca, the plant used to make cocaine, and for the smuggling of goods from neighboring Venezuela. Rebels groups and criminal gangs, many of which include former paramilitary fighters, sometimes fight for control of trafficking routes and drug crops.