(ROUGH CUT ONLY - NO REPORTER NARRATION)br Vehicles carrying 25 Egyptian prisoners depart from an Israeli prison on Thursday, setting in motion a phased prisoner exchange that will see the release of a U.S.Israeli dual national accused by Cairo of espionage.br Israel's security cabinet approved on Tuesday a deal struck with Egypt to swap 25 Egyptians for the Israeli national in a step seen as easing strains between the strategic neighbours.br The U.S.-brokered deal was reached shortly after a successful Egyptian-brokered swap between Israel and Hamas Islamists that freed captive Israeli soldier Gilad Shalit in exchange for more than 1,000 Palestinian prisoners.