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Venezuelan President Hugo Chavez on Sunday urged Colombian rebels to lay down their weapons, unilaterally free dozens of hostages and end a decades-long armed struggle.

Chavez sent the uncharacteristic message to the Revolutionary Armed Forces of Colombia, or FARC, saying their ongoing efforts to overthrow Colombia's democratically elected government were unjustified.

"The guerrilla war is history," Chavez said during his weekly television and radio program. "At this moment in Latin America, an armed guerrilla movement is out of place."

Such declarations were unexpected from Chavez, who has long been accused of giving the rebels refuge. A self-described socialist, he called on world governments to remove the FARC from terrorist lists earlier this year, suggesting the group is in fact a legitimate insurgency.

Colombia's government claims that a laptop recovered from a FARC camp in March shows a history of deep collaboration between the rebels and Chavez — something the Venezuelan leader denies.

But addressing FARC's new leader Alfonso Cano on Sunday, Chavez said, "I think the time has come for the FARC to free everyone they have in the mountains. It would be a great, humanitarian gesture, in exchange for nothing."

In the past, the FARC has said it would be willing to swap hostages for guerrillas imprisoned in Colombia and the United States.

Carlos Lozano, who has mediated between the government and rebels, told Caracol radio Sunday that he had re-established contact with the FARC in hope of facilitating the release of more hostages.

Lozano, editor of a communist newspaper, said that while he had not spoken directly with Cano, "everything is going the right way".

Yet a FARC statement posted Sunday on a Web site sympathetic to its cause suggested the group is far from laying down its arms.

Written by rebel leader Luciano Marin Arango, alias "Ivan Marquez," and dated June 5, the statement demands that new elections be called to oust Colombia's government and Congress. The FARC's "strategic objective is the taking of power for the people," the statement said.

It also claimed that Colombian President Alvaro Uribe has backed plans to kill Chavez and leftist Ecuadorean President Rafael Correa.

Colombia's government did not immediately respond to those charges.

While the rebels freed six hostages to envoys of Chavez earlier this year, they have said they won't release any others — including former Colombian presidential candidate Ingrid Betancourt and three U.S. defense contractors — without a comprehensive deal.

Prospects dimmed in March with a cross-border Colombian raid on a rebel camp in Ecuador that killed a FARC leader, prompting Chavez and Correa to briefly send troops to their borders with Colombia.

But on Sunday, Chavez appeared to change his tune.

"You in the FARC should know something: You have become an excuse for the empire to threaten all of us," he said, referring to the U.S. "The day that peace arrives in Colombia, the empire will have no excuses."

The U.S. sends hundreds of millions of dollars a year to Colombia's government, which uses it to fight guerrillas and the world's largest cocaine industry.

Latin America expert Bruce Bagley said he believes Chavez may be distancing himself from the FARC because he no longer wants to be associated with "an illegal and terrorist organization" tarnished by drug trafficking, kidnapping and extortion.

"Chavez, as he has in the past, is correcting his course to burnish his image at home and abroad," said Bagley, chairman of international studies at the University of Miami. "Chavez is making the only smart policy move available to him publicly. He may not mean it. Only time will tell."

Chavez's comments could improve Venezuelan relations with Colombia, which have been strained for months amid allegations that Chavez has been aiding the FARC.

While the guerrillas openly admire Chavez, he has repeatedly denied supporting them, saying his government's contact with them has been aimed only at securing the release of rebel-held hostages.

Colombia's government has shown journalists dozens of documents recovered from a dead rebel leader's laptop, saying they show extensive ties between Chavez and the FARC, including offers to send them at least $250 million.

In its statement, the FARC said the laptop was a fake, planted in the rebel camp by Colombian security forces.

Colombia's chief prosecutor meanwhile said a Venezuelan National Guard officer was among four people arrested along the two countries' shared border with tens of thousands of Kalashnikov rounds that Colombian authorities said were destined for the FARC. The Kalashnikov is the FARC's standard weapon.

Two of the men had Venezuelan identity papers and one claimed to be a sergeant in the National Guard, prosecutor Mario Iguaran announced Friday in a statement. The four were captured in eastern Colombia, close to its porous border with Venezuela.

Colombia's foreign minister has asked Venezuela to help investigate, and on Sunday, Venezuela's foreign ministry announced it was cooperating.

Inside Colombia, a huge black market supplies leftist guerrillas, right-wing death squads and drug cartels with weapons.