A judge sentenced 39 former police and government officials to jail terms ranging up to 26 years Friday for a peasant massacre two years ago, which sparked a wave of unrest in southwestern Mexico.

Seventeen peasants were gunned down on June 28, 1995 as they headed for a rally to protest political repression and poor living conditions.

Witnesses said as many as 300 state policemen stopped the two trucks they were riding in and opened fire without warning. Videotapes later showed the officers placing guns in the victims’ hands.

Judge Adolfo van Mester Roque sentenced 28 police officers to 24 years each in prison, and handed down jail terms ranging from six months to 26 years to 11 former state officials for their involvement in the murders. The slayings near the town of Aguas Blancas triggered nationwide protests and shook up a decades-old political system that maintained power over poor villages high above swanky Acapulco.