MOSCOW, July 28 (RIA Novosti) - Iranian authorities have refused permission to hold a ceremony in memory of those killed during post-election riots in June, the country's Fars News Agency said on Tuesday.

Opposition politicians Mir Hossein Mousavi and Mehdi Karroubi requested that the country's authorities allow them to hold a service to mourn those killed in riots after the controversial reelection of President Mahmoud Ahmadinejad on June 12. They had planned to hold the ceremony on the 40th day after the deaths.

"Neither individuals nor political groups have received permission to hold a ceremony or a demonstration," Fars quoted an interior ministry official as saying.

Iran's political crisis has continued since the wave of post-election protests triggered by alleged vote rigging. Over 20 people were killed and about 1,000 arrested during the riots.