(ROUGH CUT - NO REPORTER NARRATION)br br REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE CONTENT OF THIS VIDEO, OBTAINED FROM A SOCIAL MEDIA WEBSITEbr br Amateur video purports to show rebels shooting down a Syrian army helicopter on Monday while it was bombarding the Damascus neighbourhood of Jobar, as heavy fighting broke out between rebels and troops loyal to President Bashar al-Assad in the district.br br The witnesses said a helicopter was engulfed in flames after it was hit by a projectile during a burst of gunfire and then came down in the nearby district of Qaboun.br br Video footage taken by activists also showed a burning helicopter falling to the ground.br br Reuters is unable to independently verify the content of this video.br br Syrian state television said in a news flash a helicopter had crashed in Damascus, but offered no further details.