Mexico's Zapatista rebel group has declared a state of emergency, putting its troops on alert and sending its leadership into hiding.
In a statement issued Monday, the Zapatistas said they are calling all troops back to their bases and are evacuating their leadership to ensure their safety.
The group says its leadership will do its work clandestinely for an indefinite period of time. The group also shut down its radio station.
Civil rights activists say the declaration was likely prompted by some action by the Mexican army.
The Zapatistas are based in Mexico's southern Chiapas state and have made their name as a champion of Indian rights. They first came to national prominence in 1994 when they led an armed uprising.