The United States has launched its first Predator drone strike in Libya, as Misrata rebels claimed victory over Moamar Gaddafi's troops who have retreated from front lines. NATO says the drone strike targetted a multiple rocket launcher which had been used against civilians in Misrata. The Libyan government's retreat in Misrata appears to be a significant setback for Muammar Gaddafi's forces hastened by NATO air strikes. Misrata, the last large city held by rebels in western Libya, had been under a punishing government siege for nearly two months and hundreds of civilians have died in the fighting.