In this May 20, 2010, file photo, American hikers Shane Bauer, left, Sarah Shourd, centre, and Josh Fattal sit at the Esteghlal hotel in Tehran. (Associated Press)

Iran announced Thursday that one of three Americans jailed for more than a year will be released Saturday to mark the end of Islamic holy month of Ramadan.

The detained Americans — Sarah Shourd, 31; her boyfriend, Shane Bauer, 27; and their friend Josh Fattal, 27 — have been held in Iran since July 2009, when they were arrested along the Iraqi border.

Iran has accused them of espionage; their families say that the three were hiking in Iraq's largely peaceful mountainous northern Kurdish region and that if they crossed the border, it was accidental.

Reporters were told by text message from the Culture Ministry to come to the same hotel where the Americans' parents were allowed to meet them recently to witness the release.

"Offering congratulations on Eid al-Fitr," the message said, referring to the holiday marking the end of the fasting month.

"The release of one of the detained Americans will be at Saturday, 9 a.m. at the Estaghlal hotel." It did not specify which one.

Later Thursday, Bak Sahraei, second counsellor of Iran's UN mission, confirmed that Shourd would be the one set free.

Shourd, 31 has told her mother she has serious medical problems. Her mother said her daughter told her in a telephone call in August that prison officials have denied her requests for medical treatment. The mother said they talked about her daughter's medical problems, including a breast lump and precancerous cervical cells.

The gesture to release a hiker could be a calculated move by Iran to soften international criticism of its judiciary. Iran has faced a growing storm of protest over a stoning sentence for a woman convicted of adultery that has been temporarily suspended.

It is common in the Islamic world to mark the Eid al-Fitr holiday by showing clemency and releasing prisoners. Ali Reza Shiravi, the head of the foreign media office at the ministry confirmed that he had sent the message summoning reporters to the hotel.

The hikers' detention has become entangled in the confrontation between the United States and Iran. Iranian leaders have repeatedly suggested a link between their jailing and that of a number of Iranians by the United States whose release Tehran demands.