Rebel forces in Libya have made significant advances in recent weeks, according to NATO officials. They've taken larger control of the northwest, including parts of Brega and Misrata, and are currently engaging forces loyal to Muammar Qaddafi in the western city of Zawiya, home to Libya's only functioning oil refinery. With these advances, rebel forces are now closing in on Qaddafi's stronghold of Tripoli, seizing approaches to the city, while NATO forces dominate the skies and Mediterranean coast. (NATO aircraft have conducted more than 7,200 strike sorties since June.) Qaddafi remains defiant in the face of attacks and global diplomatic pressure, and his forces continue to exact a heavy toll on rebel forces and civilians. Gathered here are images from the past several weeks of the civil war in Libya as it appears to be reaching a turning point. Also see earlier entries: DIY Weapons of the Libyan Rebels, and Three Months of Civil War in Libya.