MercoPress. South Atlantic News Agency

Far-right militiamen lay down weapons.

Eight hundred far-right militiamen laid down their weapons on Tuesday in a ceremony the government hoped would bring peace closer but which was condemned by human rights activists as a travesty.

The overwhelmingly male, camouflage-clad young combatants of the Cacique Nutibara Block, who controlled the city's sprawling slums at gunpoint, laid assault rifles and black armbands in a heap before government peace commissioner Luis Carlos Restrepo in a Medellin conference center.

The government hopes the disbanding of the Nutibara will lead to the prompt dissolution of its parent organization, the 13,000-strong United Self-Defense Forces of Colombia. This far-right band, known by its Spanish initials AUC, is blamed by Colombian and U.S. authorities for countless assassinations and acts of torture in a dirty war against leftist rebels.

"The road to peace is open in Colombia," said Carlos Castano, one of the AUC's top leaders who could not attend the ceremony because of dozens of outstanding arrest warrants but who spoke in a message played on a giant television screen.

Skeptics doubt the sincerity of the Nutibara's demobilization, which was broadcast live and accompanied by formal speeches by officials and militiamen. But it was the first concrete result of peace talks that President Alvaro Uribe began with the AUC late last year, despite protests from human rights groups.

"Instead of handing these criminals a microphone, the government should be concentrating on arresting them and bringing them to justice," said Jose Miguel Vivanco, executive director of the Americas Division of Human Rights Watch.

Other human rights groups have also questioned the peace process with the paramilitaries, as well as a government-sponsored bill, now in Congress, to allow illegal combatants to stay out of jail by serving house arrest or paying fines.

Uribe's bill would also benefit Marxist rebels if they end a four-decade war that claims thousands of lives a year.

Colombian courts have proven many links between the AUC and sectors of the armed forces, which have worked together to kill Marxist guerrillas, and several senior officers have been convicted.

The AUC, which has its origins in vigilante groups set up by cattle ranchers and cocaine traffickers, is classed as a "terrorist" organization by the U.S. government. Washington says it will not drop extradition requests on drug trafficking charges for Castano and other top AUC leaders.

But the United States has not requested the arrest of Nutibara leader Luis Fernando Murillo -- alias "Don Berna" or "Adolfo Paz" -- even though U.S. officials describe him as one of Colombia's biggest drug traffickers.

The former Nutibara combatants will spend three weeks in the town of La Ceja undergoing rehabilitation courses before heading back to Medellin, where the city government will help them find legal employment.

But many questioned whether the Nutibara would really surrender its control of the slums, and, if they did, whether its former fighters would be killed by guerrilla foes.

There have been several demobilizations by Marxist guerrilla groups and far-right fighters in Colombia's bloody history. While some former rebels are now prominent politicians, many others have been murdered or returned to illegal activities.