EDITORS' NOTE: Reuters and other foreign media are subject to Iranian restrictions on their ability to film or take pictures in Tehran. A masked Iranian student, supporter of opposition leader Mirhossein Mousavi, has a photo of the Islamic revolution's father, Ayatollah Ruhollah Khomeini, stuck on her head during a rally in central Tehran December 13, 2009. The opposition expressed concern that the authorities were preparing to step up action against it after official media said pro-reform students had torn up a picture of Khomeini, during a rally last Monday.