BOGOTA -- Security forces have killed civilians, and have covered up the killings by dressing up the bodies as Marxist guerrillas, according to testimony in an annual United Nations human rights report released yesterday.
Last year, UN investigators said, they saw an increase in allegations of extrajudicial executions that, the report said, attributed to soldiers and police.
Those officials often presented the killings as deaths of guerrillas in combat, said a report, which was issued by the office of the UN High Commissioner for Human Rights.
The report covers the year 2005.
''Cases were recorded in which commanders themselves had allegedly supported the act of dressing the victims in guerrilla garments to cover up facts and simulate combat," the report said.
The government had no immediate response to the report. It has said that any member of its security forces found cooperating with the paramilitaries would be jailed.
Colombia is in a four-decade guerrilla war involving Marxist insurgents and far-right militias.
While President Alvaro Uribe, a US ally whose father was killed, allegedly by the insurgents, has negotiated a peace arrangement with the ''paras" and has reduced crime rates through his tough security policies, the UN report says grave rights violations continue.
''Both the lack of full acknowledgment of the problem by the government, as well as the absence of sufficient relevant actions by authorities, impeded correction," the report said.
More than 22,000 paramilitaries have surrendered guns, in an agreement promising reductions in jail terms of as many as eight years for crimes such as torture and massacre.
But politicians, academics, and human rights groups say the paramilitaries are not dismantling their criminal networks. They say the militias are using violence to influence the outcome of congressional elections in March, in an effort to gain political power and to avoid being extradited to the United States on drug charges.