In 2011, activist Samira Ibrahim, 26, was detained by Egyptian soldiers and subjected to a virginity test that she said made her feel as though she had been raped. She spoke out and sued the Egyptian military.
Last year, Time magazine named her to its list of the World's Most Influential People. On Friday, she was to have been one of 10 women to receive the International Women of Courage Award.
On Tuesday, the State Department was alerted by the Holocaust Museum to contentious tweets it said came from Ibrahim's account.
"Today is the anniversary of 9/11. May every day come with America burning," read one. Another was offensive to Jews.