Relatives of soldiers accused of homicide hold a banner during a protest against the government in Mexico City on Oct. 11, 2014. The banner reads, "Mr. President. Enough of military unjustly imprisoned." Mexican lawmakers announced Thursday that the massacre of 22 civilians by government troops in Tlatlaya in June 2014 was “illegal, excessive, and a disproportionate use of force.” Reuters

A military massacre that resulted in the deaths of 22 civilians was “illegal, excessive, and a disproportionate use of force," members of Mexico's Congress announced Thursday. The report by a working group of the House of Representatives also determined that the mass killings were an “extrajudicial execution” and called for military officials to withdraw from public security roles that would be better served by local law enforcement, including federal and state police, TeleSUR reported.

The so-called Tlatlaya massacre that unfolded in June 2014 is one of several scandals facing the administration of Mexican President Enrique Peña Nieto, who is battling a voter recall effort. Army leaders have claimed that the soldiers were patrolling the area on June 30, 2014, when they were attacked by local criminals, resulting in a deadly shootout. Forensics experts, however, found that the victims had been shot at close range with their own guns, suggesting a mass execution. The Mexican National Commission on Human Rights also said that the crime scene was altered by government officials participating in a cover-up.

“This case was the object of a deliberate cover-up by the highest authorities in Mexico, both civil and military,” Jose Miguel Vivanco, head of the Americas division of Human Rights Watch, an advocacy group based in New York, told the Christian Science Monitor last year. “We have before us two crimes: the massacre and the cover-up.”

Seven Mexican soldiers who allegedly participated in the Tlatlaya massacre have been charged with murder and abuse of authority, among other crimes. The House of Repsentatives report will now be sent to the full Congress for review. The victims in Tlatlaya, located 100 miles west of Mexico City, included 21 men and a 15-year-old girl who had reportedly surrendered to the soldiers before being killed.

"We will continue our efforts to serve the citizenry, without suffering intimidation by unfair trials, some undoubtedly erroneous, baseless, malicious and undeserving,” said the head of the army, Gen. Salvador Cienfuegos, last year after the mass shootings were made public.

Peña Nieto's approval rating sank to an all-time low in December, with more than half of all Mexicans saying they disapproved of his administration, and 85 percent revealing that they did not trust him.