(CNN) -- The mothers of three American hikers detained in Iran more than a year ago challenged the Islamic republic Monday to halt delays in the case -- or admit it is holding the three as "bargaining chips."
Protesters on Saturday held rallies in the United States and elsewhere to mark the one-year anniversary of the detentions of Shane Bauer, Sarah Shourd and Josh Fattal. The three were detailed July 31, 2009, after they allegedly strayed across an unmarked border into Iran while hiking in Iraq's Kurdistan region.
"We wonder how many more times Iran is going to say that our children's case is a judicial issue without doing anything at all to resolve it," said the statement Monday from Cindy Hickey, Nora Shourd and Laura Fattal.
"As Iranian news reports note, the Foreign Ministry announced in January that Shane, Sarah and Josh would be tried 'soon.' It is now August and our children are in their second year of detention. They remain held in almost complete isolation without any semblance of due process in violation of Iranian and international law.
"If Iran believe it has any reason to charge our children, it should do so without delay and give them a fair trial in a public court of law. If it does not have any evidence against them -- as we know to be the case -- it should release them immediately."
Tehran has accused the three hikers of being spies, which they deny. Iran's intelligence minister has hinted the country may consider releasing them in exchange for the release of Iranian prisoners, according to state media. President Barack Obama called for their release in a statement Friday, saying "their unjust detention has nothing to do with the issues that continue to divide the United States and the international community from the Iranian government."
The hikers' mothers were allowed to visit them in May in Tehran. The mothers said Monday that at the time, their children told them they had not been questioned for several months.
"Iran should stop dragging its feet and act according to its own laws or finally come clean and admit that it is holding our children as bargaining chips," the statement said.
Iran's state-run Press TV rebutted reports Saturday that the hikers' detainment is related to the case of an Iranian scientist who accused the United States of abducting him last month. Shahram Amiri returned to Iran two weeks ago. The United States has said Amiri was in America of his own volition.