Two Iranian warships have sailed through the Suez Canal to the Mediterranean Sea, canal officials say.
Iranian officials have said the warships are heading to Syria for training, a mission Israel has described as a "provocation".
The ships exited the canal at 1330 GMT, a canal authority source told Reuters.
It is believed to be the first time since Iran's 1979 Islamic Revolution that Iranian warships have passed through the waterway.
The Iranian vessels entered the canal at 0545 local time (0345 GMT) and passed into the Mediterranean at 1530 (1330 GMT)," the source at the canal authority told Reuters.
"Their return is expected to be on 3 March," the source added.
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, says the BBC's diplomatic correspondent Jonathan Marcus.
He says the two Iranian vessels do not represent any significant threat to either the Israeli navy or US vessels in the Mediterranean.
The ships involved are the Alvand - thought to be a British-built Vosper Mark 5 class frigate - and a supply vessel, the Kharg, also British-built.
The Alvand, a missile-carrying frigate, was launched in 1968. It is an impressive vessel by the standards of the Iranian navy, but no match for comparable Western warships nor the sophisticated missile boats of the Israeli navy, our correspondent says.
What is clear is that this deployment is not a direct response to the current upheavals in the Middle East, he adds.
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 - well before the protests that have swept the leaders of Tunisia and Egypt from power.
But coming in the wake of these political changes the Iranian deployment will be seen by the Israeli in particular as even more destabilising, our correspondent says.
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.
Last week, Israeli Foreign Minister Avigdor Lieberman said: "To my regret, the international community is not showing readiness to deal with the recurring Iranian provocations.
"The international community must understand that Israel cannot forever ignore these provocations."