BOGOTA - Colombian President Alvaro Uribe acknowledged that his army used the Red Cross emblem in its bloodless July 2 rescue of 15 hostages, a move the humanitarian agency swiftly denounced as "abusive."

Uribe allowed Wednesday that one army official wore a vest with the International Committee of the Red Cross (ICRC) emblem but said that it was because the official was nervous about the operation and there were many leftist rebels on the scene.

So "the official took a piece of cloth out of his pocket with the initials CICR (ICRC) on it, and he put it on his vest; we are sorry that this has happened," Uribe said, suggesting there was no effort at deception.

CNN television reported that it had viewed unpublished photos and video of the rescue in which a military official is seen using the emblem of the international humanitarian organization, in what some said could be deemed a "war crime."

Uribe said he presented his apologies to the ICRC on Wednesday morning, but Red Cross outrage over the incident was immediate.

"The emblem of the Red Cross needs to be respected in all circumstances and cannot be used in an abusive manner," the ICRC said in a statement from Bogota.

In Geneva, ICRC spokeswoman Florian Westphal said: "The respect of the emblem is crucial so the ICRC can bring help to people affected by the conflicts in Colombia or elsewhere."

Westphal said it was important that Uribe "had admitted the error that had been committed."

The organization did not say whether it would take any action as a result of the misuse.

Hours after the dramatic rescue of the hostages from the hands of the Revolutionary Armed Forces of Colombia (FARC), the country's army commander General Mario Montoya publicly denied -- in Uribe's presence -- that his men used emblems from the humanitarian organization.

"Not one insignia, Mr. President, not from the Red Cross or anything like it, nor from any humanitarian mission whatsoever," Montoya had said, in describing the operation which tricked the Marxist rebels into handing over the 15 hostages, including French-Colombian politician Ingrid Betancourt and three US defense contractors.

It was not immediately clear how Uribe's revelation will affect the ICRC's role in ongoing attempts to free an estimated 700 hostages still held by FARC.

ICRC, which reports having 318 staff in Colombia including 57 non-Colombians, has been active in dialogue with the rebels for years, as various groups including the Colombian, French and Swiss governments have sought to negotiate hostage releases.

On its website, the ICRC warns that "perfidy" -- "making use of the emblem in time of conflict to protect combatants or military equipment" -- violates the Geneva Conventions.

"Perfidious use of the emblem is a war crime in both international and noninternational armed conflict," the ICRC states on its website.

"The ICRC, a neutral and impartial humanitarian organization, must enjoy the trust of all the parties to the conflict to be able to carry out its humanitarian work," said an ICRC statement released in Bogota.

The lawyer of Gerardo Aguilar and Alexander Farfan, the two FARC members captured in the operation, said his clients told ICRC representatives they had been tricked by the soldiers' use of emblems of the Red Cross and of the Telesur television network.

"They have said it on several occasions, indicating that the (Colombian) army pretended to be the International Red Cross, and that three or four people in the operation used Red Cross emblems," attorney Rodolfo Rios told AFP.

Colombia's general prosecutor Mario Iguaran said he believed the act of "perfidy" could not be applied in the hostage-rescue case, because "the objective of the military operation was to liberate hostages and not to attack or harm the adversary."

Uribe said the name of the official in the rescue operation would not be disclosed to protect him from threats and "because we do not want to harm his career."

© 2008 Agence France Presse