Complex sentence: It has seen extensive fighting between the various armed groups in Colombia's ongoing civil war and is currently controlled by the Autodefensas Unidas de Colombia (AUC), the main paramilitary group.
Split into simpler sentences: It has seen extensive fighting between the various armed groups in Colombia's ongoing civil war. As a result, it is currently argued to be predominantly under the influence and control of the United Self-Defense Forces of Colombia (AUC), the main paramilitary group.