Mexico's highest court ordered the release of nine more people convicted in a 1997 massacre of Indians, ruling Wednesday their convictions were based on illegally obtained evidence. New trials were ordered for 16 others.

It was the second time this year the Supreme Court overturned the sentences of people convicted for the slaying of 45 people at Acteal, a village in southern Chiapas state. The court released 20 people in August and ordered new trials for six.

The court cited irregularities including failure to provide interpreters for suspects who speak the Tzotzil language. Prosecutors also apparently took pictures of the suspects and showed them to witnesses, who later identified the men as perpetrators.

The court has finished reviewing the cases of all 51 people who appealed their convictions in the case.

The massacre in Acteal on Dec. 22, 1997, was the worst single instance of violence during a conflict that started when the leftist Zapatista movement staged a brief armed uprising in early 1994 to demand more rights for Indians in Chiapas.

Paramilitaries with alleged ties to government figures attacked a prayer meeting of Roman Catholic activists who sympathized with the rebels. Over several hours, the assailants killed 45 people, including children as young as 2 months old.