Two Iranian warships have sailed through the Suez Canal to the Mediterranean Sea, according to canal officials.
Iranian officials have said the warships are heading to Syria for training, a mission Israel has described as a "provocation".
It is believed to be the first time since Iran's 1979 Islamic Revolution that Iranian warships have passed through the waterway.
Iran's request stated the vessels would have no military equipment, nuclear materials or chemicals on board, the Egyptian defence ministry is quoted as saying.
A Suez Canal official said earlier Egypt could only have denied transit through the strategic waterway in case of war.
But the significance of the deployment is entirely diplomatic, reports the BBC's diplomatic correspondent.
He says the two Iranian vessels do not represent any significant threat to either the Israeli navy or US vessels in the Mediterranean.
Iran's semi-official Fars news agency reported in January that Iranian navy cadets were going on a year-long training mission through Suez and into the Mediterranean - before the protests that have swept the leaders of Tunisia and Egypt from power.
Israel considers Iran a threat because of its controversial nuclear programme, development of ballistic missiles, support for Lebanese and Palestinian militant groups, and Tehran's repeated anti-Israel rhetoric.