TEHRAN, Iran — Iranian security forces beat anti-government protesters with batons Wednesday on the sidelines of state-sanctioned rallies to mark the 30th anniversary of the U.S. Embassy takeover. The counter-demonstrations were the opposition’s first major show of force on Tehran’s streets in nearly two months.

The opposition sought to display unity and resolve after relentless crackdowns on their protests following the disputed June presidential election. Though the crowds were far smaller than during last summer’s outrage, authorities were ready with the same sweeping measures: dispatching paramilitary units to key locations and disrupting mobile phones, text messaging and Internet access to frustrate protest organizers.