Muslim Student Followers of the Imam's Line was a group of student supporters of Khomeini that occupied the U.S. embassy in Tehran on 4 November 1979 after the ex-Shah of Iran was admitted to the United States for cancer treatment. Although the students later said they did not expect to occupy the embassy for long, their action received official support and triggered the Iran hostage crisis where 52 American diplomats were held hostage for 444 days.