Mexico’s Ministry of Security is reporting that at least 20 inmates are dead and 12 wounded at a border prison in Matamoros, Mexico after rioting broke out Saturday.  Matamoros is right across the border from Brownsville, Texas.

The rioting appeared to have started after two inmates started fighting and many others joined in.  Prison officials called in for additional support from the Mexican Navy and federal security officials.

Fights of this kind are not uncommon due to overcrowded conditions and rival narco gang members being housed in the same prisons.  Just last week a fight broke out in a Monterrey, Mexico prison that left 7 prisoners dead and in July a riot inside a Juarez prison left 17 inmates dead.