Dozens die in Mexico prison as rival drug gangs fight
Over 40 people have died in a prison fight in northern Mexico.
Security officials said members of rival drug cartels confronted each other with stones and home-made weapons in the jail north of the city of Monterrey.
An investigation is under way to establish if some of the prison guards colluded in the fight by unlocking the doors separating two wings of the prison.
The BBC's Will Grant in Mexico City said cartels are a powerful force in Mexican prisons.
19 Feb 2012