In Libya, US drones carried out a number of strikes in Misrata as well as on suspected missile sites in capital Tripoli giving tactical advantage to the rebels. As the drones stuck with precision at Gaddafi's snipers perched on tall buildings in the strife-torn city Misrata , the rebels launched attacks to drive them out gaining vital ground in the town which has witnessed battle for more than four weeks. Misrata has been besieged by Gaddafi's forces for nearly two months with Human Right groups estimating that hundreds of civilians being killed. Tripoli street is a site where two western photojournalist were reported to be killed on Wednesday. The announcement of deployment of armed drones over Libya was made by Defence Secretary Robert Gates . He said this would give allied forces “precision capability” in military operation. US officials said at least two predators would remain in the Libyan airspace at all times and the Hellfire missile equipped UAVs would prove more effective than A-10 ground attack aircraft. Al Jazeera reporting from rebel stronghold of Benghazi said military advisors from UK, France and Italy had started arriving. Senior Republican Senator John McCain visited Libyan rebel headquarters in Benghazi.