The world is watching in horror as Israel and Iran spiral into a brutal exchange of strikes that has seen US-made warplanes batter targets across the Islamic Republic while hypersonic and ballistic missiles rain down over Tel Aviv.

The conflict now threatening to plunge the Middle East into war was triggered on Friday when Israel launched Operation Rising Lion - the culmination of work by the military and Mossad spy agency to sabotage Iran's ambition for nuclear weapons.

Attack drones emerged from a clandestine base on Iranian soil to destroy Tehran's air defence systems before fighter jets launched hundreds of strikes on strategic military assets and nuclear facilities.

Israel also wiped out top military chiefs, the head of the revolutionary guard's aerospace forces and more than a dozen nuclear scientists. Subsequent raids took out senior intelligence officers, according to Israeli PM Benjamin Netanyahu.

Iran struck back with fury, unleashing hundreds of missiles - including unstoppable hypersonic weapons - to target Israel's defence ministry, military sites and some residential areas.