Rebel fighters from the Nafusa Mountains located in northwestern Libya claimed Aug. 13 to have seized two key towns along the last remaining supply lines that connect Tunisia to Tripoli. One of these supply lines enters the Libyan capital from the south, traversing through Gharyan, which rests on the easternmost point of the mountain chain. The other more important route passes through the refinery town of Zawiya along a well-paved coastal road which connects Tripoli to Tunisia. If both these towns (especially the much larger population center of Zawiya) fall under permanent control of rebel forces, Tripoli risks being cut off from its primary sources of fuel. U.N. sanctions bar the export of petroleum products to Libya, and it is primarily the poorly enforced border controls with Tunisia that allow for fuel shipments to enter Gadhafi-held territory. The direct coastal road from Ras Jedir is the primary route.