A judge in El Salvador is reopening a probe into one of the most notorious massacres in recent history: the murder of hundreds of people in the village of El Mozote.

Human rights advocate Ovidio Mauricio told The Associated Press on Saturday that Judge Jorge Guzman Urquilla has accepted his organization's request. It's based on a ruling by the country's Supreme Court that overturned a law that granted an amnesty for war crimes during El Salvador's 1979-1992 civil war.

A postwar truth commission concluded that the army massacred at least 500 people in El Mozote and surrounding villages in three days in December 1981. Victims' rights advocates put the number closer to 1,000.

Researchers say the villagers had tried to remain neutral, but the army suspected them of rebel sympathies.