(AGI) Moscow, July 18 - Russia has warned that it may respond,should cross-border fire from Ukraine continue. Speaking onRossiya state television, Foreign Minister Sergei Lavrov saidhe was convinced that in response to specific targeting ofRussian territory the source of such an attack should, as aone-off measure, be destroyed. He added that Moscow felt thatwhat had happened thus far reflected a lack of professionalismon the part of those manning Ukrainian positions. . .