CAIRO - Egypt accused Iran on Thursday of "unacceptable interference" in its domestic affairs for having criticized the Egyptian army's removal of elected president Mohamed Morsi last week.
The incident signaled a return to cooler relations between the two Middle Eastern powers after an attempt at rapprochement under Morsi, who hails from the Islamist Muslim Brotherhood.
Iran on Monday called the ousting of Morsi after mass protests against him a "cause for concern" and suggested that "foreign hands" were at work in the Arab state.
Egypt shot back on Thursday, expressing "extreme discontent" with the Islamic Republic's comments and saying they reflected a "lack of precise knowledge of the nature of the democratic developments Egypt is witnessing".
"This represents unacceptable interference in Egypt's internal affairs," the foreign ministry said in a statement on its Facebook page. Egypt made similar remarks to Turkey after its Islamist-rooted government criticized Morsi's ouster.
Western states have been cautious so far in characterizing the military overthrow of Morsi. Washington has specifically avoided referring to it as a "coup", a word that would force it to halt aid including $1.3 billion per year for the army.
Relations between Egypt and Iran broke down after the 1979 Iranian revolution, when Egypt gave sanctuary to the deposed shah. Many Egyptians harbor strong feelings against Iran.
Morsi tried to improve ties after he was elected in 2012. Iranian President Mahmoud Ahmadinejad visited Cairo in February, the first visit by an Iranian leader in more than three decades.
But the two countries remained sharply divided on Syria. Shi'ite Muslim Iran is the main backer of President Bashar Assad while Morsi, often under pressure from hardline Sunni Muslim allies, backed Syria's largely Sunni rebels.
Egypt historically has much stronger ties to Gulf Arab states who have vied with Iran for regional influence. Kuwait, Saudi Arabia and the United Arab Emirates provided Cairo's cash-strapped government $12 billion in aid this week.