Iran holding 15 British sailors

At least 15 British sailors are being detained by Iranian navy vessels in the Gulf.

The British Ministry of Defence confirmed the detainment, adding that it was "urgently" seeking clarification from Tehran.

Details of the incident remained sketchy.

“The British government is demanding the immediate and safe return of our people and equipment,” the Defence Ministry in London said, adding that the sailors had been detained after a routine boarding of a merchant ship in Iraqi waters.

Foreign Secretary Margaret Beckett summoned the Iranian ambassador to seek clarification over the incident, which comes amid mounting tension between Tehran and the West over its nuclear program.

"At approximately 10.30 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.

"The boarding party had completed a successful inspection of a merchant ship when they and their two boats were surrounded and escorted by Iranian vessels into Iranian territorial waters.

"We are urgently pursuing this matter with the Iranian authorities at the highest level and on the instructions of the Foreign Secretary, the Iranian ambassador has been summoned to the Foreign Office.

News reports had originally suggested that there were American military personnel among those detained in the Shatt al-Arab waterway close to the southern stretch of Iraq's border with Iran.

However, the US Navy later said none of its military personnel were involved.

"We can confirm that there are no US military involved or held in this incident,'' a spokesman for US Naval Central Command said.