DAMASCUS, Sept. 22 (Xinhua) -- Syrian President Bashar al-Assad on Saturday slammed the attack that targeted an Iranian military parade in southern Iran as "a criminal and cowered act," local news reported.

Assad's condemnation appeared in a letter of condolence sent to his Iranian counterpart, Hassan Rouhani, in which Assad said that Syria stands by Iran in terms of terrorist acts, according to the state news agency SANA.

He said that Iran, which is the Syrian government main regional ally, has stood against terrorism in Syria, calling on the countries that support terrorist groups to review their stances and stop supporting and financing terrorist acts across the world.

Earlier in the day, four armed men attacked a military parade in Ahvaz city in southern Iran which marked the anniversary of Iran-Iraq war in 1980-1988. Two were killed and the other two were arrested.

The attack also killed 11 soldiers who attended the parade.

Reports said that 31 others were injured, among whom most were from the Iranian Islamic Revolution Guards Corps (IRGC).

The IRGC Spokesman Sardar Sharif said that the attack was carried out by Al-Ahvazieh group, a group supported by Saudi Arabia which claims to fight for the rights of the Iranian Arabs in the southern Khuzestan province.

Iran denounces the Al-Ahvazieh as "a separatist and terrorist group."