Mexico City - Mexican security forces appear to have committed "two more major atrocities," with evidence showing police unlawfully killed at least 11 unarmed civilians in two incidents this year, Human Rights Watch said Wednesday.
Witnesses have contradicted official accounts that federal police acted appropriately in two episodes of violence in the western state of Michoacan that killed eight civilians in January and 42 gang suspects in May, the New York-based organization said.
In both cases, witnesses saw police officers kill unarmed civilians after the initial confrontations were over, HRW said.
"Based on the available evidence, it appears we're looking at two more major atrocities by Mexican security forces," said Daniel Wilkinson, managing director of the organization's Americas division.
"While the government insists that police acted appropriately in both cases, what witnesses describe clearly involves extrajudicial killings," Wilkinson said in a statement.
Mexican troops and police have been under scrutiny following high-profile cases of alleged abuse in the country's drug war.
On January 6, soldiers and police broke up a protest held by members of civilian self-defense groups in the city of Apatzingan and detained 44 people.
A 19-year-old survivor whose name was changed to "Alejandro" told HRW that after the protest, a convoy of about 100 people wielding only clubs and sticks headed to the outskirts of city, where they believed police were holding wounded companions.
Police cars blocked the convoy and began to shoot at the civilians without warning, said Alejandro, whose account was corroborated by two other witnesses, according to HRW.
Alejandro, who hid under a truck after being wounded, said he saw police pull another man hiding under another truck and shoot him in the head.
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Another injured man was ordered to his knees, shot in the head and his body dumped in a car.
Police planted guns next to both bodies, according to the witness.
A federal official said shortly after the episode that all but six of the victims were killed in crossfire by the civilians' own guns, while it was impossible to determine who shot the other two.
An official in the attorney general's office told HRW in August that there were "no elements" to charge any officers.- 'Shot in the back' -
The second episode took place on May 22 in Tanhuato, where police clashed with Jalisco New Generation drug cartel members at a ranch, leaving 42 suspects and one officer dead.
The lopsided death toll raised questions over whether the officers committed abuses, but officials said at the time that it was due to superior police training and equipment.
HRW said, however, that three survivors declared that at least nine civilians were executed.
The witnesses told a human rights researcher, who requested anonymity, that a few civilians engaged in a shootout with police but that many dropped their weapons and did not fire back.
At least five who attempted to flee into fields were shot in the back by police, the witnesses said.
The witnesses said officers took seven people into the main ranch house after the initial gunfight had subsided and killed four of them, shooting three and burning one inside a warehouse.
Officials told HRW that federal prosecutors are investigating the case.