U.S. Defense Secretary Ashton B. Carter says the U.S. Marines picked up earlier this week by Iranian authorities in Iranian territorial waters had made a “navigational error”.

Ashton Carter

Ashton Carter

According to Reuters, Carter said on January 15, 2016: “The information that they have given us, and through their commanders, is that they did stray accidentally into Iranian waters due to a navigation error.”

Carter added: “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 the Iranian boats and discovered they were inside of the territorial waters of Iran.”

Press TV reported on Wednesday that Admiral Ali Fadavi had said on Tuesday: “Ten sailors aboard two CB-90 patrol boats, who were reportedly moving between Kuwait and Bahrain for a training mission, were taken into custody.”

The report adds that the marines, including nine men and one woman, had taken their boats within three miles of Farsi Island in the Persian Gulf when they were picked up.

The marines were released on Wednesday following a number of telephone exchanges between Iranian and U.S. diplomats.