Rio De Janeiro: At least 55 people were found dead after violent clashes broke out among rival drug factions in several prisons in northern Brazilian state of Amazonas, officials said on Monday.

The clashes began on Sunday during visiting hours at the Anisio Jobin prison in Manaus city. Of the 15 inmates who died, some were reported to have been asphyxiated, while others were stabbed with sharpened toothbrushes.