A Mexican judge has acquitted three military personnel of the extrajudicial killing of 15 suspected gang members during a confrontation in June 2014, the attorney general’s office said late Friday.

The clash took place in Tlatlaya on the southern fringes of the state of Mexico, which borders the violence-plagued states of Guerrero and Michoacan.

Authorities said at the time the dead were suspected drug gang members, and the military had acted in self-defense. Twenty-two people died in the incident.

But months later, foreign media reported there was evidence of extrajudicial executions, a version later upheld by Mexico’s CNDH national human rights body.

Mexico’s military has been accused on multiple occasions of extrajudicial killings and torture during a decadelong war against the country’s brutal drug cartels.