A rebel sniper fires at government forces.<br/> <br />This is the Syrian city of Aleppo and video obtained by Reuters appears to show the Free Syrian Army battling forces loyal to President Bashar al-Assad.<br/> <br />Challenging Assad's control of the capital Damascus and Syria's largest city Aleppo has upped the ante in recent days.<br/> <br />But Assad has vowed to fight to the death in a conflict that has killed some 38,000 people and risks sucking in other countries.<br/> <br />The chief international mediator said on Thursday Russia and the United States would seek a "creative" solution to the crisis, suggesting coordination between the major powers might be possible after months of disagreement.<br/> <br />Rebels have made advances on Damascus and taken several military bases in recent weeks but Assad's superior military power continues to dominate, flattening opposition-held areas with aerial and artillery strikes.
