Iran's top three reformist leaders demanded ruling clerics end the crackdown that followed the country's disputed presidential election, warning Tuesday that the waves of arrests and bloodshed would only radicalize the opposition.

Defeated presidential candidates Mir Hossein Mousavi and Mahdi Karroubi as well as former president Mohammad Khatami met late Monday and called for the release of those arrested during the protests and in sweeps afterward, the report on Mousavi's official Web site said.

The meeting — the first of its kind by the biggest names in the reform movement — appeared to be part of an attempt to resuscitate the opposition after the crackdown unleashed by police, Revolutionary Guards and pro-government Basij militia shattered massive protests that sprung up after the June 12 election.

Police say 20 protesters were killed, hundreds injured and more than 1,000 arrested in the violence and in sweeps that followed. Since the clampdown, there have been no major street protests for more than a week.

The government has closed universities and dormitories, fearing a new round of protests on Thursday, which is the 10th anniversary of a 1999 attack by Basij and police on protesting students.

Mousavi on Monday vowed to continue his campaign against a government he said lacks legitimacy — but hinted he was dropping the strategy of protests and moving to political action, including forming a party.

A moderate political party close to the powerful former President Akbar Hashemi Rafsanjani issued its own statement condemning the results of the elections and called for the release of political activists.

"Due to unhealthy trend of elections, widespread irregularities and the support extended by majority members of the Guardian Council to a specific candidate (the incumbent), the result of this election is not acceptable," the Kargozaran Sazandegi Party.

Rafsanjani remains a high level figure in the political hierarchy and is a bitter enemy of Ahmadinejad, though he has kept his distance from the post-election turmoil.

The pro-reform camp maintains Mousavi was the real winner in the election and accuses Iran's ruling system of faking results that showed a victory for incumbent hard-line President Mahmoud Ahmadinejad. Karroubi came last in the official results.

Iran's supreme leader Ayatollah Ali Khamenei, who has the final say on all state matters, has publicly sided with Ahmadinejad.

Police say most of those arrested during the demonstrations have been released. Still, dozens of protesters, pro-reform politicians and journalists are still being held, and arrests have continued.

"The useless wave of arrests must end immediately and all those detained without committing the least crimes must be released. Also, security and military forces must return to their bases," Mousavi, Karroubi and Khatami said in a statement after their meeting.

They said there was a need to "end the existing security atmosphere" because its continuing would lead to the "radicalization of political activities."

The statement also deplored "savage and shocking attacks" by pro-government Basij militia against protesters.

The three also denounced what they called "inhuman, illegal" confessions that state media have said some of the detainees have made. Iran's hard-line leaders have been trying to erase any lingering doubts about the legitimacy of Ahmadinejad's government by portraying the unrest as sparked by foreign meddling.

State media have reported that some detainees have confessed to what amounts to collaboration with foreign powers against the Iranian state.

Mousavi separately met family of a protester killed in post-election riots, saying innocent blood won't be wasted.

"Blood shed unjustly won't be wasted," the reformist Web site http://www.norooznews.net quoted Mousavi as telling the family Tuesday.

French President Nicolas Sarkozy, meanwhile, demanded the liberation of a young French academic detained after taking photos of Iranian protests and accused of espionage.

Clotilde Reiss, 23, was arrested last week at the airport as she was about to leave Iran after a five-month stay during which she taught French at Isfahan University.

"These accusations of espionage are high fantasy," Sarkozy said at a news conference Tuesday.

European officials and diplomats said European Union nations are also not ruling out tougher diplomatic action against Iran to win the release of a British Embassy employee who remains in detention. Envoys from the 27-nation bloc will meet Friday to discuss a possible travel ban against senior Iranian officials to protest the detention, they said, speaking on condition of anonymity because of the sensitivity of the issue.

British calls to coordinate a temporary pullout of EU ambassadors from Tehran is also still being considered, but many member states fear punishing the Iranian government too harshly could damage years-old efforts to negotiate with Tehran over its disputed nuclear program.

The detentions of nine local staff at the British Embassy last week cranked up Iran's standoff with the West. All but one has been released, but the remaining staffer could face prosecution for fomenting protests.

Supreme leader Khamenei warned the West against sharp criticisms of Tehran over its crackdown, saying Monday that anything considered "meddling" would damage ties with Western nations.