An American university student and women's rights activist has been arrested in Iran while visiting her family and conducting research for her graduate degree thesis, Amnesty International said in a statement. Esha Momeni, a graduate student at California State University, Northridge, was arrested while driving on a highway in Teheran by officials who said they were traffic police, the human rights group said. The officials said the Oct. 15 arrest was for a traffic offense, but after arresting her, police took Momeni to her family's home and confiscated her computer and other materials related to her research on the Iranian women's movement, the London-based rights group said in a statement posted on its Web site earlier this week. Momeni, who is a member of the California branch of Change for Equality - an Iranian women's rights group - was later taken to Evin prison, Amnesty said. The Teheran facility is notorious for holding political prisoners.