Colombian security forces committed "a significant number" of murders over the past decade, often for personal profit, and few of the perpetrators have been punished, according to a report published Thursday by an independent U.N. human rights expert.
Philip Alston, the U.N.'s investigator on extrajudicial executions, said in his 36-page report that the number of so-called "false positive" killings by military members surged in 2004.
The term refers to killings in which civilians were lured to remote locations before being shot by soldiers who then dressed their victims in combat garb, or placed a gun in their hand, to make them appear like guerrillas killed in gunfights.
Alston, who made a fact-finding mission to Colombia last year, said the killings didn't appear to be part of government policy but rejected official claims they were isolated incidents.
"There have been too many killings of a similar nature to characterize them as isolated incidents carried out by individual rogue soldiers or units," he said.
Estimates of the number of killings over the past decade vary between several hundred to more than 2,000, Alston said.
Although such killings have been less frequent since the government took steps to prevent them in 2007, few of the perpetrators have been tried, he said.
"The current rate of impunity for alleged killings by the security forces, up to 98.5 percent by some credible estimates, is way too high," said Alston, citing a figure by the Washington-based non-governmental group U.S. Office on Colombia.
Officials at Colombia's mission to the U.N. in Geneva could not immediately be reached for comment.
In his report, due to be presented to the U.N. Human Rights Council on June 3, Alston also addressed killings carried out by paramilitary and guerrilla groups.