U.S. Defense Secretary Ashton Carter
U.S. Defense Secretary Ashton CarterReuters

U.S. Defense Secretary Ashton Carter on Thursday addressed this week’s incident in which a group of American sailors were detained by Iran after their Navy boats strayed into Iranian waters in the Persian Gulf.

According to Carter, who was quoted by The Associated Press (AP), it appears a navigational error caused the crews to accidentally enter Iranian waters.

"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," Carter was quoted as having said in an interview in Miami with Fusion network.

He later flew to Tampa to meet with leaders of U.S. Central Command, which oversees the U.S. military in the Middle East. At a news conference at Central Command headquarters, he declined to discuss the circumstances in more detail, saying only that 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, Carter said, "Obviously I don't like to see our people being detained by a foreign military."

"We need to give these guys the opportunity to tell us what was really going on," he added, according to AP.

Iran released the 10 navy sailors on Wednesday, a day after detaining them. Iranian media reported that the 10 were released after it was determined they had entered Iranian waters "unintentionally," and after the U.S. "apologized" for the incident, as per Tehran's demands.

White House spokesman Josh Earnest later denied the reports, saying he was not aware of any discussions between Washington and Tehran about an American apology for the incident and noted one "certainly" had not been given.

Meanwhile on Thursday, the 10 sailors were back with their American fleet. Navy officials said the 10 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 ensue, according to AP.

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. Gen. Lloyd Austin, head of Central Command, said the equipment is being inventoried.