Montazeri’s death pushed Iranian authorities into a difficult spot. They were obliged to pay respects to one of the patriarchs of the 1979 Islamic Revolution and the one-time heir apparent to Ayatollah Ruhollah Khomeini.

But officials also worried that Montazeri’s memorials could become new rallying points for opposition demonstrations. The ayatollah broke with Iran’s clerical leadership and became a vehement critic, denouncing Supreme Leader Ayatollah Ali Khamenei and calling the postelection crackdown the work of a dictatorship.

Mourners shouted “Death to the Dictator” and other slogans in displays of anger against Iran’s ruling establishment during the procession in Qom, a city of shrines and clerical seminaries about 60 miles (100 kilometers) south of Tehran, witnesses said.

The Iranian election and subsequent protests were named the top Twitter news event of 2009, with #iranelection the top trending news hashtag.