Iran has summoned the British charge d'affaires in Tehran to protest what it said was the illegal entry of British naval personnel into Iranian waters.
Britain's Defense Ministry says the British sailors and their two boats were surrounded by Iranian ships and escorted from Iraqi waters into Iran's territorial waters.
U.S. Naval Forces Central Command, the U.S. Fifth Fleet, also insists that the seizure was in Iraqi territorial waters.
Nick Lambert is the commander of the "H.M.S. Cornwall," on which the sailors were based.
"We know [our] helicopter reported that they saw the boats being moved up the Shatt al-Arab waterway toward an Iranian base up there, and we know that there was no fighting, there was no engagement with weapons or anything like that," Nick Lambert, the commander of the "H.M.S. Cornwall," on which the sailors were based, said. "It was entirely peaceful."
Sailors Believed Unharmed
Britain's Defense Ministry says Iran's ambassador in London has been summoned, and that Britain is demanding the sailors' immediate and safe release.
The British Foreign Office stresses that it is "urgently pursuing [the] matter with Iranian authorities at the highest level" and demands the return of the "people and equipment."
Commander Lambert said his seamen appear to be unharmed.
"We've been assured from the [little] communication we've had with the Iranians at the tactical level that the 15 people are safely in their hands," he said.
A similar incident took place in 2004, when Iran detained eight British service personnel for three days, accusing them of crossing into Iranian waters. Those sailors were released unharmed.
British and U.S. ships patrol the Persian Gulf in an effort to prevent shipments that might help feed the violent insurgency in Iraq.
Earlier today, a senior British military officer repeated accusations by London and Washington that Iranians are helping foment violence in Iraq.
Diplomatic tensions between Tehran and the international community are high on the eve of an expected vote on March 24 on possible further sanctions to convince Iran to halt sensitive nuclear activities.
(compiled from agency reports)