DUBAI - Iranian Supreme Leader Ayatollah Ali Khamenei blamed countries outside the Middle East on Monday for the region's turmoil and the Shi'ite cleric said regional states backing radical Sunni Islamists would be damaged by conflict.Khamenei, the most powerful man in Iran, made the comments in a meeting with Oman's Sultan Qaboos who was in Tehran on a visit Iranian media said may be an effort to mediate between the United States and the Islamic Republic.If so, Khamenei's comments appeared to be a rebuff of those efforts."The main reason behind the status quo in the region is interference from outside the region," the state news agency Fars quoted Khamenei as saying in a meeting with Qaboos.Khamenei and other top officials in the Islamic Republic frequently call on the United States and European powers to stop what they call interference in the Middle East, accusing them of a plot to take over the region.His other comments appeared to be directed at Sunni Muslim states in the Middle East such as Saudi Arabia, Qatar and Turkey which are supporting rebels fighting to topple Syrian President Bashar al-Assad, a close ally of Shi'ite Iran."Unfortunately, a Takfiri group has been formed with the support of certain regional states which is in conflict with all Muslim groups, but supporters of this stream should know that this fire will burn them too," Khamenei said."Takfiri" is a derogatory term for hardline Sunni Islamists, who accuse Shi'ites and others of being infidels. Iranian officials have warned of dire albeit unspecified consequences for the United States and its allies if they intervene in Syria in response to last week's apparent chemical weapons attack outside Damascus which killed hundreds of people.