Iran's current Supreme Leader Ayatollah Ali Khamenei, left, seen here in a photo from a January  2008 visit to the Imam Shrine, where a scheduled annual celebration has been reportedly cancelled due to security concerns.  Grandson of the late Ayatollah Khomeini, caretaker of his grandfather's shrine, is at the right.  (Photo courtesy official website of the Supreme Leader of Iran)

The grandson of the late Ayatollah Khomeini, spiritual leader of the 1979 Iranian revolution, has reportedly cancelled an annual celebration at his grandfather's shrine due to security concerns.

Seyyed Hassan Khomeini, who as grandson is also caretaker of the Imam Khomeini mausoleum site, is said by Iranian news sources to have released a statement announcing cancellation of the event, at which several controversial speakers, including hardline clerics  Seyyed Ahmad Khatami, Ahmad Jannati and recently re-elected Iranian president Mahmoud Ahmadinejad, were scheduled to address those assembled.

Khomeini has been openly critical of the current leadership in Iran, and refused to attend the recent inauguration of Ahmadinejad, whose June election was heavily disputed and led to violent protests.  Khatami has called in recent weeks for the execution of opposition leaders involved in those protests.

The move comes just as Iranian parliament has approved most of Ahmadinejad's cabinet choices, including Brigadier General Ahmad Vahidi as Defense Minister, wanted by Interpol in the 1994 bombing of a Jewish center in Argentina.

It also comes as Press TV is reporting that President Barack Obama of the United States has sent a second letter to the administration of Iran since the unrest began in June.