GRANADA, Colombia — Street vendor Israel Rodriguez went fishing last month and never came back. Two days later, his family found his body buried in a plastic bag, classified by the Colombian army as a guerrilla fighter killed in battle.

Human rights activists say the February 17 death is part of a deadly phenomenon called “false positives” by which the armed forces allegedly kills civilians, usually peasants or unemployed youths, and represents them as leftist guerrillas.

A macabre facet of a general increase in “extrajudicial killings” by the military, the killings are a result of intense pressure to show results in its American-funded war against leftist insurgents, the activists say.

Rodriguez’s sister Adelaida said her brother had served three years in the army and was neither a guerrilla nor a sympathizer.

“He never made any trouble for anyone,” she said, adding that she believes the army killed him to “gain points.”

Killings like these have spread terror here in the southeastern state of Meta. Last year the state led Colombia in documented cases of extrajudicial killings, with 287 civilians allegedly killed by the military, according to the Colombian Commission of Jurists. That’s a 10% increase from the previous year.

Although there appear to be no official — or unofficial — tallies of alleged “false positives,” human rights activists say they believe they are rising along with the overall increase of killings by the military, based on their discussions with victims’ families and analysis of circumstances surrounding individual cases.

“It’s quite likely, because the same scenario appears over and over again in the cases I review. Victims last seen alive in civilian clothing later are found dead dressed in camouflage and claimed as guerrilla casualties,” John Lindsay Poland of Fellowship of Reconciliation, a New York-based human rights group, said.

The killings have risen in recent years amid an emphasis on rebel death tolls as the leading indicator of military success, the groups say.

Even Colombian officials acknowledge that soldiers and their commanders have been given cash and promotions for upping their units’ body counts.