Colombia's ELN rebel force said Friday it had made an "error" earlier in the day when it announced the release of two Dutch journalists it kidnapped in the north of the country four days ago.

The pair remain "in perfect condition," the rebel group's radio station ELN Ranpal said on Twitter.

"On the captured Dutch men, we had received a report at noon on their release but we have not been able to corroborate it properly," the station said.

"The error was that Ranpal had received a report and did not corroborate it through internal channels."