(CNN) -- Iranian authorities have released an American-born graduate student on bail after holding her in prison for nearly a month, an Amnesty International spokeswoman said Tuesday. Graduate student Esha Momeni was arrested last month in Iran and jailed after an alleged traffic violation. Esha Momeni, 28, had been working on a project on the women's movement in Iran when she was arrested October 15 for an alleged traffic violation, according to California State University-Northridge and Change For Equality, an Iranian women's movement. She had been held in solitary confinement in Tehran's notorious Evin Prison, Change For Equality said. "We're really happy she's been released on bail," Elise Auerbach of Amnesty International said Tuesday. She said she learned of Momeni's release Monday through Amnesty's researchers in London, England, and from Momeni's family and friends.
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Amnesty: Esha Momeni's parents gave Iranian government deed to their house
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Momeni shooting footage for project on Iranian women's movement when arrested
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Fellow student tells paper Momeni "determined to better the lives" of Iranians
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Momeni could still be charged with propaganda against the state, Amnesty says
Auerbach said Momeni is not the only woman involved with @placeholder who has been jailed recently; at least three women who worked with the group are being detained, she said.