Conservatives welcomed confessions by defendants rejecting prior claims of election fraud. Critics said the statements were forced.
Thousands of people clashed with security forces in the streets after a symbolic 40-day period since the death of protesters. Thirty years ago, such protests helped bring down the Shah.
Iran's theocracy, wary that mourning can turn to political protest, shuts down commemoration for opposition "martyr."
In a striking move Tuesday, Supreme Leader Ali Khamenei personally called for a detention center to be closed, citing mistreatment, while President Ahmadinejad sanctions repressive tactics.
Growing unease over conditions of detention for hundreds is helping opposition organize, and exposing some splits in Iran's conservative ranks.
President Mahmoud Ahmadinejad fired his intelligence minister Sunday after being forced to remove his first vice president, a close adviser.
Within hours of the Friday sermon, grainy cellphone videos surfaced showing crowds surging away from tear-gas plumes and kicking the canisters back toward police.
The influential former president appealed for the rule of law to be respected, an open national dialog, and a release of political prisoners