EDITORS' NOTE: Reuters and other foreign media are subject to Iranian restrictions on leaving the office to report, film or take pictures in Tehran.

A boy smiles as he plays on a tank at a war exhibition held by Iran's revolutionary guard to mark the anniversary of the Iran-Iraq war (1980-88), also known in Iran as the "Holy Defence", in southern Tehran September 26, 2011. REUTERS/Morteza Nikoubazl (IRAN - Tags: POLITICS MILITARY ANNIVERSARY TPX IMAGES OF THE DAY)