Protests raged on at Iranian universities and in some cities on Saturday as Supreme Leader Ayatollah Ali Khamenei warned the country's "enemies" may try to mobilise workers after failing to topple the Islamic government in more than two months of unrest.One of the boldest challenges to Iran's clerical leaders in decades, the protests have been gaining steam, frustrating authorities who have blamed Iran's foreign enemies and their agents for orchestrating the disturbances.The wave of unrest erupted in September after Kurdish-Iranian woman Mahsa Amini died in the custody of the country's morality police after she was arrested for wearing clothes deemed "inappropriate".In 1979, a combination of mass protests and strikes by oil workers and bazaar merchants helped to sweep the clergy to power in Iran's Islamic revolution.On Saturday, activist HRANA news agency said sit-down strikes and protests were taking place on two dozen campuses in the capital, Tehran, and in major cities including Isfahan, Tabriz and Shiraz with slogans including "Freedom, freedom, freedom"."