MEXICO CITY (Reuters) - A Mexican judge said the country’s attorney general has not “exhaustively, adequately and effectively” investigated the extrajudicial executions of 22 people allegedly committed by the military in 2014, a human rights organization said on Sunday.

The Miguel Agustin Pro Juarez Human Rights Center (Prodh) said the judge ordered the attorney general’s office to “carry out a series of proceedings to immediately clarify the case and establish responsibilities, including the chain of command involved in the illegal order to shoot” the victims.

“This lack of due diligence is one of the many forms taken by the unacceptable cover up of serious human rights violations in Mexico,” said Prodh, which represents a survivor of the shooting, Clara Gomez Gonzalez.

Federal judge Erik Zabalgoitia Novales said the inadequate investigation was a violation of the victims’ rights, according to Prodh.

The attorney general’s office and Federal Judiciary Council did not immediately respond to requests for comment.

A military tribunal in 2016 pardoned six of seven soldiers allegedly involved in killing the 22 suspected cartel henchmen in Tlatlaya, a small town a couple of hours southwest of Mexico City.

Authorities said at the time that those killed were members of a cartel and that the armed forces acted in self defense.

Later, international media organizations reported that there was evidence the killings were extrajudicial, and Mexico’s National Human Rights Commission later echoed that conclusion.