Escorted by 500 soldiers and with Black Hawk helicopters buzzing overhead, 59 paramilitary warlords were transferred from a former holiday camp to a maximum-security prison. The government said it feared an escape plot.

Friday's move to Itagui prison -- home to some of Colombia's most hardened criminals -- is likely to come as a shock to the right-wing commanders, who for the past few months have enjoyed privileges unfound in any of Colombia's violence-ridden jails.

The drug-funded paramilitary militias are accused of some of the worst atrocities in the Andean nation's long-running civil conflict and are listed as foreign terrorist organization by the United States.

Their transfer to a regular prison is likely be applauded by the United Nations and foreign governments, who have accused the government of being too soft on the warlords in the face of mounting evidence they've been flaunting the terms of their 2002 peace deal.

As part of a negotiated deal with the government, until Friday the leaders were been held at La Ceja, a former retreat center reminiscent to many Colombians of the country club-like jail specially built in the 1990's to hold deceased drug kingpin Pablo Escobar.

President Alvaro Uribe's decision to send the leaders to the Itagui prison, 150 kilometers northwest of Bogota, comes as he's been struggling to insulate himself from a widening scandal over which several of his allies in Congress stand accused of conspiring with the same militias.

As the number of his allies hauled to testify before the Supreme Court increases almost daily -- so far three pro-government lawmakers have been arrested and at least seven more are under investigation -- Uribe has taken a hardened stance against the paramilitaries.

In a speech Thursday, he blamed the recent killings of two demobilized commanders on those in La Ceja and threatened to revoke the benefits they enjoy under the peace process, including suspension of their extradition to the United States to answer drug trafficking charges.

One of the incarcerated commanders, Ernesto Baez, told Caracol Radio Friday the authorities were carrying out the killings in order to blame the paramilitaries.

Officially, though, the government said it was acting on "persistent rumors of a possible escape," Interior Minister Carlos Holguin said Friday.

The official did not provide further details about the nature of those rumors except to say the came from the DAS intelligence agency, which has itself long been dogged by accusations of working hand in glove with the paramilitaries.

The paramilitary leaders have angrily denied they were plotting to escape.

Recently, the leaders have intensified their complaints about the peace process, which limits their prison time to a maximum of 8 years, saying the government was betraying promises made at the bargaining table.

They had demanded the government pass a decree outlawing their extradition to the United States.

The militias were created by landowners and drug-traffickers to battle leftist rebels who held sway over much of Colombia's countryside.

Also Friday, the army said in a statement that 17 soldiers were killed and four injured when leftist guerrillas attacked their patrol in northeastern Colombia.

The attack by the Gabriel Galvis unit of the Revolutionary Armed Forces of Colombia occurred late Thursday near the town of Abrego, 300 kilometers northeast of Bogota.

Luis Miguel Moreli, governor of Norte de Santander state where the attack took place, said the army and rebels were locked in heavy combat in the area.