BOGOTA - The Colombian terror group FARC announced Tuesday its intention to release an unspecified number of hostages, in a statement released hours after tens of thousands of people marched in major cities calling for an end to kidnappings.

President Juan Manuel Santos said that he was not willing to exchange any jailed terrorists in excahge for hostages, as the terrorist group had suggested, but he said that he was open to a future dialogue if there are signs of "true political will."

In a message without much detail, the FARC communique promised "the unilateral release of prisoners of war that we announced in our earlier letter, even though some of them were killed in the senseless military rescue attempt, " The message came in a letter released Tuesday on the Marxist terrorist group's website (www.farc-ep.co).

The FARC tried to claim that four hostages killed on November 26th were the result of the a military attack on their camp. The Colombian military found the bodies of three policemen and Army Sergeant Jose Libyan Martinez, the oldest guerrilla hostage, who had been held hostage since December 21, 1997.

"We deeply regret that four of the six prisoners of war that we would unilaterally release (...) have died in an irrational attempt to rescue them by the Colombian army, as they marched to the place that we were planning to deliver them," the communique stated.

After learning the contents of the letter, President Santos rejected any prisoner exchange and warned that there would be no dialogue with the rebels until they could verify a genuine desire for peace.

"One way to express this desire is to free the hostages unilaterally, without conditions and without a show, just release them," the president told the radio station Radio RCN Colombia.

"Then we will see how we can sit down and see if there is room for dialogue or not. But to speak of a humanitarian agreement, exchange, no," he continued.

The last peace talks between the FARC and the Colombian government failed for nearly a decade.

The day began with a massive march of tens of thousands of people, many dressed in white, demanding the return of hostages from the jungles and mountains, and expressed their distaste for the violence suffered by Colombia after nearly half a century of continuous armed conflict perpetuated by leftist terrorist groups.

"We're sick of them, for their crimes. The FARC have no real ideology, they're only narco-terrorists," said Lia Velazquez, an official of the regional government of Antioquia (northwest), in the central Plaza Bolivar in the capital.

President Santos himself joined the protest in the town of Villeta, near Bogota, accompanied by the police sergeant Luis Alberto Erazo, the sole survivor of the killing of the four military hostages.