Four Salvadoran soldiers arrested over the weekend for their alleged involvement in a 1989 massacre will make their first appearance before the Supreme Court Monday, according to local media.

The four military men are the first to be arrested of the 17 soldiers wanted by international police. They are accused of participating in the brutal killing of six Jesuit Spanish priests, a housekeeper and her teenage daughter on a university campus in San Salvador.

Spain has long requested the soldiers' arrest and extradition to face trial in Spain, since five of the six murdered Jesuit scholar-priests were Spanish.

The Salvadoran Supreme Court will determine which judicial body will be assigned to handle the extradition hearing of the former soldiers. The court already approved Friday the extradition of one of the men, former Colonel Inocente Orlando Montano Morales, accused of ordering the attacks.

The murders took place during El Salvador's 12-year civil war, which saw 75,000 people killed and 8,000 more disappeared. According to a truth commission report, 95 percent of the violence and human rights abuses during the war were committed by the U.S.-backed Salvadoran army and paramilitary groups.

The six Jesuit priests were executed by a battalion of special forces that were trained by the U.S. during an offensive Nov. 16, 1989.

The brutal killing of the peaceful religious figures and two innocent women became a symbol of El Salvador's brutal civil war and helped erode U.S. support for the country's violent right-wing government.

Lisandro Quintanilla, the defense lawyer who represents 13 of the 17 wanted soldiers, has argued the recent arrests are illegal since El Salvador's Supreme Court denied earlier extradition requests in 2012.

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