MONTERREY, Mexico -- Mexican security officials say seven inmates have died in a prison riot that may have been set off by the arrest of a top drug cartel lieutenant.
Nuevo Leon state security spokesman Jorge Domene says about 60 inmates at a prison near the city of Monterrey burned mattresses and attacked each other with improvised knives.
Domene said Thursday that military and federal authorities were called after prison staff failed to control the fight.
Domene says the outburst may have been a response to Wednesday's arrest of Carlos Oliva Castillo, who is allegedly a leader of the Zetas cartel. He allegedly ordered an arson attack on a Monterrey casino that killed 52 people in August.