( AP ) - Iran on Wednesday blamed what it described as "U.S.-backed terrorists" for the fatal assassination of a Shiite cleric during a religious festival, saying Washington seeks to incite ethnic and religious tensions to undermine the government.
Unknown gunmen shot dead Shiite cleric Mahdi Tavakoli late Tuesday night as he was addressing a religious festival in a mosque in Khash, southeastern Iran, the official IRNA news agency reported Wednesday.
"The U.S.-backed terrorists martyred this cleric," IRNA said.
Local police chief, Mohammad Ghaffari, said the fatal assassination was aimed at provoking "rifts between Shiite and Sunni Muslims."
"Terrorists, backed by the U.S., seek to create instability in this province through their blind actions ... and provoke differences between Shiite and Sunni Muslims," IRNA quoted Ghaffari as saying.
He added that investigations were underway to identify those responsible.
Tehran has increasingly raised the alarm that the United States may attack it or try to foment an uprising against the government amid the escalating standoff between the two countries over Iran's nuclear program and the turmoil in Iraq.
The United States and several of its Western allies fear that Iran is using its nuclear program to produce an atomic weapon - charges Iran denies, saying its aim is to generate electricity.
Iranian officials have also raised concerns that Washington might be inciting members of Iran's many ethnic and religious minorities against the Shiite-led government, which is dominated by ethnic Persians.
Iran has faced several ethnic and religious insurgencies and armed attacks by opposition groups on some of its borders in recent years - though none have amounted to a serious threat to the government.
A bomb explosion in southeastern Iran earlier this month killed 11 members of Iran's elite Revolutionary Guards. A Sunni Muslim militant group called Jundallah, or God's Brigade, which has been blamed for past attacks on Iranian troops, claimed responsibility for the bombing.
Besides the violence in the southeast, ethnic Arab Sunni militants have been blamed for bombings in the western city of Ahvaz - including blasts in 2006 that killed nine people. Iranian Kurdish guerrilla groups based in northern Iraq have also stepped up attacks inside Iran.