US sailors 'made navigational error' in Iran
US defence secretary Ash Carter has said it appears a navigational error caused the crews of two navy boats to stray into Iranian waters in the Persian Gulf, where they were detained overnight.
"They did not report this navigational error at the time. It may be that they were trying to sort it out at the time they encountered Iranian boats. We don't know that fully yet," he said.
Mr Carter later flew to Tampa, Florida, to meet leaders of US Central Command, which oversees the US military in the Middle East, but at a news conference at Central Command headquarters, he declined to discuss the circumstances in more detail, saying it would be prudent to first finish debriefing all 10 returned sailors.
Asked his view of the video released by Iranian media showing the Americans kneeling aboard their boats with their hands on the heads, Mr Carter said, "Obviously I don't like to see our people being detained by a foreign military."
He said this was the scene as depicted by Iranian media and he wanted to hear from the US crews before commenting further. "We need to give these guys the opportunity to tell us what was really going on," he said.
Less than a day after being detained on Iran's Farsi Island in the Gulf, the 10 US sailors were back with their American fleet. The navy said they were undergoing what the military calls "reintegration", a series of interviews and physical and mental health examinations to ease their return to duty. A navy investigation will folllow.
The navy has given no indication that the 10 were injured or mistreated or that the weapons or equipment aboard the boats were tampered with while in Iranian custody.
Head of Central Command, General Lloyd Austin, said: "For the most part the gear that we deployed with was largely there when we got the boats back. Whether or not there are singular pieces of equipment missing, we'll determine that once we've completed the inventory."
A complete picture of what happened is unlikely to be available for days, but the central cause for the crews' entering Iranian waters was the navigational slip, which was apparently was caused by human error rather than by an equipment malfunction, defence officials said.
The boats, known as riverine command boats, were on their way from Kuwait to Bahrain.
The navigational error cited by Mr Carter was compounded by some sort of engine trouble aboard one of the boats, another defence source said. The engine problem did not cause the boats to go off course but apparently prevented them from evading the Iranians once the crews realised they were inside Iran's territorial waters.
The navy realised the boats were missing when they failed to appear shipside in the Gulf for refuelling on their way to Bahrain, one official said. GPS devices aboard the boats enabled the navy to determine, after the fact, that they were in Iranian waters, but the navy was not immediately sure whether the crew members were safe or had gone overboard.
A search-and-rescue operation was mounted and at least one US ship crossed into Iranian waters to look for the crew after alerting the Iranian navy of their intentions. The Iranians did not interfere, the defence official said.
US secretary of state John Kerry used the personal relationship he has formed with Iranian foreign minister Mohammad Javad Zarif to work out the crews' release. Mr Kerry credited the quick resolution to the "critical role diplomacy plays in keeping our country secure and strong".
Mr Carter said the sailors were not on a covert mission and were simply making their way from Kuwait to Bahrain, both on the western coast of the Gulf. They ended up in Iranian territorial waters at least 50 miles offshore and were detained by the Iranian military at Farsi Island, home to an Iranian naval base.
The navy said the families of the 10 crew members were kept informed of developments once it was confirmed that the Iranians were holding them.