The motive for the explosion on July 25 remains a mystery, though some in the conference said it reflected the violence suffered by society at large in a country with soaring homicide rates and a decade-long drug cartel crackdown.

An explosive device was detonated outside the offices of the Mexican bishops' conference, directly across the street from the country's most visited religious site, the Basilica of Our Lady of Guadalupe.

Many of the graves have been discovered by desperate family members acting on their own and without the assistance of the authorities.

"We do not know the reasons why he was abducted. He did not have problems with anyone," Father Angel Vargas Uribe said. "We are not scared."

Bishop Castro has come under attack from politicians and public officials upset for voicing suspicions of corruption in Morelos, Mexico. The threats, he says, are not dissuading him, though the publicity is causing discomfort.

A parish on the Mexico-Guatemala border is preparing for Central Americans seeking safety from the gang violence that is gripping El Salvador and Honduras.

"Any migrant that arrives at the Mexican-U.S. border will be required to hire the services of organized crime," Sister Leticia said.

"This priest will not return the same...He's going to live in fear, going to live with the effects of this trauma."

Media reported the men were found one day after their abduction along the side of a highway with their hands and feet bound.

The Catholic Church in Veracruz had lobbied for the abortion ban and welcomed its approval.