Iran has announced that one of the three Americans jailed for more than a year will be released on Saturday to mark the end of Islamic holy month of Ramadan.
Reporters were told by text message from the Culture Ministry to come to a hotel 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, 9am at the Estaghlal hotel."
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 inviting reporters to the hotel.
The high-rise Estaghlal hotel near Evin prison is where the three Americans' mothers were allowed to visit them in May in a highly publicised trip.
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.
Their 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.
Nora Shourd, the mother of Sarah Shourd, said this morning that the US-based families of the hikers had seen the news reports out of Iran but had no idea if they were true or not.
"We don't know anything," Ms Shourd said. "We're trying like crazy to see what we can find out. I hope it's true - that's all I can say for sure. But I don't know if it is."
Nora Shourd had the last contact with any of the three jailed Americans, when Sarah called her on August 2 and the two spoke for three or four minutes.
AP