NEW : Officials say the death toll in grenade attack is up to 30 . President Nuevo Leon responds to attack via his Twitter account . Grenade attack reported at a casino in Mexico , in northeastern Monterrey . Up to 53 people thought trapped in the casino because of debris .
NEW : Officials say the death toll in grenade attack is up to 53 . President Felipe Calderon responds to attack via his Twitter account . Grenade attack reported at a casino in Monterrey , in northeastern Mexico . Up to 30 people thought trapped in the casino because of debris .