A pro-reform Web site said Monday that 88 Teheran University professors had appealed to Iran's supreme leader to halt violence against opposition protesters.
The letter to Ayatollah Ali Khamenei represented the latest daring challenge to the Islamic leadership, calling the attacks a sign of weakness in the ruling system.
It urged Khamenei to order arrests for the hard-line crackdown, which was increased after protesters began chanting slogans against the supreme leader. The Greenroad Web site posted the letter on Monday.
At least eight people died during clashes across Iran last month, including a nephew of opposition leader Mir Hossein Mousavi. It was the worst bloodshed since the height of the unrest immediately after disputed June presidential election.