WASHINGTON (AFP) – Three Americans detained in Iran during a hiking trip near the border with Iraq made ""a simple and very regrettable mistake,"" a companion of the trio said Thursday.

Shon Meckfessel, the fourth member of the party, did not go on the hike but explained the circumstances around the ordeal in a statement posted on news websites.
""I hope that people understand my friends' presence in the area for what it was: a simple and very regrettable mistake,"" he said.
Shane Bauer, Sarah Shourd and Josh Fattal were detained July 31 on the Iranian side of the border after hiking through the mountains from Iraq's Kurdistan region, Iranian state media has reported.
Meckfessel said he was supposed to go with them but stayed back in a hotel because he was coming down with a cold.
But he spoke by telephone with Bauer several times after the party set out and hiked to Ahmed Awa, recommended by locals as a particularly scenic spot with a waterfall, according to his account.
""That morning they had woken up early and resumed hiking along the same trail. Shane sounded very calm and content, happy to be in a beautiful environment, and made absolutely no mention of any risk whatsoever,"" he said.
""I am absolutely certain that they had no knowledge of their proximity to the Iranian border or they would have never continued in that direction.
The group was ""planning to turn around soon,"" he added, citing Shane. ""He thought we could meet up near the waterfall.""
But Meckfessel said Bauer failed to return two text messages and then called to say they were being taken into custody and to call the U.S. embassy.
Meckfessel said the group had no idea Ahmed Awa was near the border with Iran, thinking it was in another direction from the eastern Kurdish city of Sulaimaniyah.
""There is no Lonely Planet Iraqi Kurdistan, and Ahmed Awa was not on the map we'd printed out,"" he said.
The hikers had decided to go there after asking locals for suggestions about what to see after arriving in Sulaimaniyah on July 29, Meckfessel added.
""Every one of them told us to visit a place called Ahmed Awa. Not one of these people mentioned that Ahmed Awa was anywhere near the Iranian border,"" he said.
Meckfessel described the others as close friends who shared ""a deep appreciation for Middle Eastern cultures"" and who had written about their travels in the past.
The statement was posted on the websites of The Nation, New American Media and Mother Jones, publications that Bauer had written for as a freelancer.
""In late July, the four of us decided to travel from Damascus, Syria to Iraqi Kurdistan for a short vacation. Sarah had to return to work in a week.
""While going there might seem strange to Americans, the Kurdish territory is actually very beautiful and quite safe,"" Meckfessel wrote.