Eight British sailors were seized by Iran yesterday after they strayed across the Iraqi border, sparking a diplomatic dispute.
Iran's Revolutionary Guards said that three Royal Navy patrol boats had illegally entered their territory on the Shatt al Arab river and the sailors were being questioned.
The Ministry of Defence in London confirmed last night that the sailors had been detained while "delivering a boat from Umm Qsar to Basra".
A spokesman said: "The team were travelling in three boats, two Boston Whalers and one British Army Combat Support Boat, along the Shatt al Arab Waterway. The boats are unarmed but the crews were carrying their personal weapons. The Foreign and Commonwealth Office is liaising with the Iranian government to resolve the situation."
The MoD said the boats, powered by outboard motors, went missing in the early hours of yesterday while training Iraqi police in anti-smuggling operations.
It said the presence of maps and weapons in the boats was compatible with their mission and "normal in a war zone". But there were indications that the patrols may have also been watching for Iranian militants who may be crossing into Iraq.
A spokesman for the Iranian Foreign Ministry said the boats had been "confiscated" and the crews were being interrogated in order to "clarify" what they were doing in the waterway.
The Foreign Office said the British ambassador in Tehran, Richard Dalton, had been in talks with the Iranian authorities over the incident. There were reports yesterday that the captured Britons, who have not been named, would be filmed in custody by Iranian television. Iranian media said the men had admitted they made a mistake.
The incident comes at a time of heightened tension between Britain and Iran. Last month, Iranian students protesting against the occupation of Shia sites in Iraq pelted Britain's Tehran embassy with stones and home-made explosives. Britain is also seen as partly responsible for heightened European pressure on Iran's nuclear programme and its human rights record.
The incident is the latest in a series of maritime spats between Iran and its neighbours in which Tehran has forcefully asserted control over its waters. Arab states have accused Revolutionary Guard hardliners of raising tensions. Some analysts in Tehran say the boats' seizure could be intended to send a message to Western governments that they should negotiate through hardliners.
The maritime border has long been a source of dispute. Gary Sick,of Columbia University, said: "The Iranians hold to the fact that the line is the centre of the channel and they fought an eight-year war over this."Reuse content