Britain has demanded the "immediate return" of 15 British Royal Navy personnel captured at gunpoint by Iranian forces in the Gulf today.
Iran has summoned the British charge d'affairesto Tehran in protest over what it said was the illegal entry of British naval personnel into Iranian waters.
British Foreign Secretary Margaret Beckett has demanded the immediate and safe return of the HMS Cornwall servicemen
"The Iranian Foreign Ministry has seriously objected following the illegal entry of British naval military forces into our country's waters," Iranian state television reported, adding that they were detained by Iranian border guards for further investigation.
The British have said the men were taken prisoner while operating in Iraqi waters.
Iran's ambassador in London has been summoned, and Britain is demanding the immediate safe release of the sailors.
"At approximately 10.30am Iraqi time this morning, 15 British naval personnel, engaged in routine boarding operations of merchant shipping in Iraqi territorial waters . . . were seized by Iranian naval vessels," the ministry said in a statement.
It is not the first time that British servicemen have been taken captive by Iranian forces in the troubled waters between Iran and Iraq.
Eight servicemen were seized and detained in July 2004 after their patrol boats were said to have strayed into the Iranian side of the Shatt al-Arab waterway.
The men were blindfolded and held for three days during which they were paraded on Iranian TV.The United States, Britain's chief ally, has built up its naval forces in the Gulf in a show of strength directed at Iran.
Two American carriers, including the USS John C. Stennis - backed by a strike group with more than 6,500 sailors and Marines and with additional minesweeping ships - arrived in the region in recent months, ratcheting up tensions with Iran.
A Pentagon official said the Britons were in two inflatable boats from the frigate H.M.S. Cornwall during a routine smuggling investigation..
He said the confrontation happened as the British contingent was traveling along the boundary of territorial waters between Iran and Iraq. They were detained by the Revolutionary Guard's navy after inspecting a merchant ship believed to be smuggling cars, he said.
A fisherman who said he was with a group of Iraqis from the southern city of Basra fishing in Iraqi waters in the northern area of the Gulf said he saw the Iranian seizure. The fisherman declined to be identified because of security concerns.
"Two boats, each with a crew of six to eight multinational forces, were searching Iraqi and Iranian boats Friday morning in Ras al-Beesha area in the northern entrance of the Arab Gulf, but big Iranian boats came and took the two boats with their crews to the Iranian waters."
In June 2004, six British marines and two sailors were seized by Iran in the Shatt al-Arab between Iran and Iraq. They were presented blindfolded on Iranian television and admitted entering Iranian waters illegally, then released unharmed after three days