An oil tanker carrying 670,000 barrels of crude has left Libya's Ras Lanuf oil terminal, the first shipment since the port was reopened following a year of blockades by armed protesters, Reuters cited a spokesman for state-run National Oil Corporation as saying. The tanker carrying Sirtica crude left the Libyan port on Tuesday evening, the spokesman said. The shipment was a positive development for Libya's central government, which is struggling to contain fighting between rival armed factions who have clashed with rockets and artillery for a month in Tripoli.