Iran kicks off massive air defense drill

A show of force by Iran's military a week after Washington accused Tehran of firing on a U.S. drone.

Iranian state television broadcast these images of fighter planes and bombers as the government announced it was lauching one of the largest air drills the country has ever conducted.

Some 8,000 elite and regular troops are expected to participate in the maneuvers which are taking place against a backdrop heightened tension between the U.S. and Iran over Tehran's nuclear program.

This is just one of a number of military simulations Iran has carried out this year --- the U.S. and Israel say they haven't ruled out the possibility of military action against Iran.