The incident took place at approximately 1030 Iraqi time.
The British Personnel, eight personnel from the Royal Navy, and seven from the Royal Marines, were engaged in routine boarding operations of merchant shipping in Iraqi territorial waters in support of UNSCR 1723 and the government of Iraq.
Operating from HMS Cornwall, the UK 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.
The British Government is demanding the immediate and safe return of our people and equipment.
Any speculation about what might happen or the way our people may be treated could be genuinely dangerous, and the MOD urges media to refrain from such speculation whilst the Government conducts its urgent discussions with the Iranian authorities.
Next-of-kin of all personnel seized have now been informed.
In the interests of protecting their anonymity at this difficult stage, we would ask all editors to refrain from publishing or broadcasting anything that could lead to even partial identification of any of the individuals involved.
The families of the Royal Navy and Royal Marine personnel detained in Iran have stated:
“While we understand the media interest in the ongoing incident, this remains a very distressing time for all of us and our families.
We are grateful for the support shown to us by everyone involved and appreciate it, but would request that our privacy is respected."
The MOD has activated a helpline for concerned families. The number is 08457 800 900.
Speaking to the press today, Royal Navy Commodore Nick Lambert, Commander of the coalition forces operating in the North Arabian Gulf, said:
"My immediate concern obviously is for my people. I've got 15 sailors and marines who've been arrested by the Iranians and my immediate concern is that their safety and that their safe return to me is ensured. And I can assure all of the families who are listening out there that everything is being done at the highest levels of the UK government and indeed of the coalition structure that we are working under to ensure that safe return is possible.
"I'm speculating to a certain extent; we know our helicopter reported that they saw the boats being moved up the Shatt-al-Arab waterway towards an Iranian base up there and we know that there was no fighting, there was no engagement, no weapons or anything like that; it was entirely peaceful and we've been assured from the scant communications that we've had from the Iranians at a tactical level that the 15 people are safely in their hands.
"I know that my people behaved in an extremely professional way, I've been out with the boarding parties on many occasions myself. Everything I've seen from the report of the situation suggested that they reacted in impeccable fashion, totally professional, entirely in line with the rules of engagement and the direction that I have given them. And I have to say that I'm extremely impressed with what they have done, and I look forward to seeing them on their return to the vessel."