MEXICO CITY (AP) — A retired Roman Catholic bishop who was famous for trying to mediate between drug cartels in Mexico has been kidnapped, the Mexican Council of Bishops said Monday.

The church leadership in Mexico said Msgr. Salvador Rangel disappeared on Saturday and called on his captors to release him, in a statement.

The council said Rangel was in ill health, and begged the captors to allow him to take his medications as “an act of humanity.”

Rangel was bishop of the notoriously violent diocese of Chilpancingo-Chilapa, in the southern state of Guerrero, where drug cartels have been fighting turf battles for years. In an effort later endorsed by the government, Rangel sought to convince gang leaders to stop the bloodshed and reach agreements.