(ANSA-AFP) - BRUSSELS, AUG 20 - European Commission chief Ursula von der Leyen Thursday slammed a "hybrid warfare" campaign against the bloc after a Romanian jet destroyed a marine drone in an incident Bucharest blamed on Russia. "An escalating campaign of threats is underway, unsettling our citizens and seeking to divide our Union," von der Leyen said, warning the EU must step up its defence push to be able to "deter provocation and aggression." (ANSA-AFP).