1. of or pertaining to conflict or struggle within a group: an internecine feud among proxy holders.
2. mutually destructive.
3. characterized by great slaughter; deadly.
http://dictionary.reference.com/browse/intermecine
Though neither could win, the internecine argument continued on and on, so several people got hurt.
Sorry for not updating the past couple of days, I was away for the weekend without access to the internet.