Mexican police have arrested a teachers’ union leader accused of siphoning off money raised illegally from union members in the southern city of Oaxaca.
Mr. Nunez was arrested in the early hours of Sunday and taken to the federal prison of Hermosillo, in the north-western state of Sonora.
Fellow union activist Francisco Villalobos was arrested in Oaxaca.
Ruben Nunez has led a decade-long fight for better pay and working conditions.
His supporters say Mr. Nunez is innocent, accusing the Mexican government of having political reasons to arrest him.
They have set up roadblocks around Oaxaca to demand his release.
The union has also called for demonstrations in Mexico City on Tuesday and Friday.