Washington, Sha'ban 15, 1435, Jun 13, 2014, SPA -- The United States on Thursday condemned the flow of Russian fighters and arms into Ukraine, following alleged reports that the Ukrainian military is using phosphorus bombs in an attack in Slovyansk. "We have long condemned the flow of Russian fighters and arms into Ukraine as destabilizing and a violation of Russia's Geneva commitments," State Department spokeswoman Jennifer Psaki told reporters. "If these latest reports are true, which I do not have confirmation of, this incursion marks a serious and disturbing escalation of the crisis in eastern Ukraine," Psaki added. --SPA 13:34 LOCAL TIME 10:34 GMT www.spa.gov.sa/w