A powerful U.S.-made anti-tank missile is being used by an armed, rebel group in the fight against president Bashar Al-Assad's regime in Syria's raging civil war. Evidence of the missiles rebel hands first appeared in April. Videos posted online by a well-organized insurgent group operating in the country's north show the missile in action. These are first serious US-built arms used in the civil war. As Reuters reports, such weapons in hands of the rebel group signals "a further internationalization of the conflict, with new rockets suspected from Russia and drones from Iran also spotted in the forces of President Bashar al-Assad. "None of that equipment, however, is seen as enough to turn the tide of battle in a now broadly stalemated war, with Assad dominant in Syria's central cities and along the Mediterranean coast and the rebels in the interior north and east. "It was not possible to independently verify the authenticity of the videos or the supplier of the BGM-71 TOW anti-tank rockets shown in the videos. Some analysts suggested they might have been provided by another state such as Saudi Arabia, a U.S. ally, probably with Washington's acquiescence. "U.S. officials declined to discuss the rockets, which appeared in Syria around the same time Reuters reported that Washington had decided to proceed with plans to increase aid, including delivery of lower-level weaponry. "U.S. officials say privately there remain clear limits to American backing for the insurgency, given the widely dominant role played by Islamist militants. A proposal to supply MANPAD surface-to-air missiles was considered but rejected."