TEHRAN, August 28 (RIA Novosti) - Iranian President Mahmoud Ahmadinejad has called for severe punishments for those behind the unrest that followed the June 12 presidential election, Press TV said on Friday.

In a speech before Friday prayers, Ahmadinejad denied electoral fraud, calling the vote "healthy" and the unrest "painful," the state English-language TV channel reported. He said certain people who have been deceived by the enemy's schemes tried to shake the Islamic establishment's foundations.

"I call upon security and judicial officials to decisively and mercilessly act on those who committed inhumane acts in the guise of the friends since they inflicted damage on people and tarnished the image of the establishment, security and police forces," the president said.

Ahmadinejad also called on authorities to treat those deceived with "Islamic compassion." He lashed out at Western countries for interfering in Iran's domestic affairs, and advised them to make up for their "blunders," the channel reported.

Ahmadinejad's re-election triggered mass protests by defeated candidate Mir-Hossein Mousavi's supporters. At least 30 people were reported to have been killed and about 1,000 arrested in post-election violence in the capital Tehran and some other cities, in Iran's most severe unrest since the 1979 Islamic Revolution.

Iranian authorities have agreed to release around 140 prisoners detained in the riots, but around 200 people, including 50 opposition activists, remain in jail.

Ayatollah Ali Khamenei, Iran's Supreme Leader, moved to prevent possible death penalty sentences against prominent dissidents on Thursday by dismissing allegations they were linked to foreign powers.

"I don't accuse the leaders of the recent events of being linked to foreign countries, including the U.S. and Britain, since the issue has not been proven for me," Ayatollah Khamenei was cited by international media.

The prominent Islamic cleric warned that the trials would deepen the crisis of confidence within the country and further damage Iran's reputation.

Ayatollah Khamenei's remarks came as German Chancellor Angela Merkel joined calls for harsher sanctions against Iran, which has defied international demands to halt uranium enrichment, when the five permanent Security Council members and Germany meet next week.

The Islamic Republic is suspected of seeking to build nuclear weapons under the guise of a civilian program, a claim Tehran has denied. China and Russia have spoken out against new sanctions.