A suicide bomber killed at least two senior commanders of Iran's Revolutionary Guards in the country's southeast Sunday during an attack in which 60 people died or were wounded, Iranian media reported.
State television suggested that a Sunni rebel group called Jundollah (God's soldiers) -- linked by some analysts to the Taliban -- was the likely suspect for the most severe attack on the Revolutionary Guards in recent years.
"Attacker detonated explosives strapped to his body during gathering of tribal heads," state Press TV said in a headline, adding that civilians and tribal leaders were also among the victims.
The Revolutionary Guards blamed "foreign elements" linked to the United States for the killings, which underlined deepening instability in Iran's southeast bordering Pakistan and Afghanistan.
Tehran accuses the United States of backing Jundollah to create instability in the country but Washington denies this.
State broadcaster IRIB said the attack occurred in the morning at the gates of a conference hall in the city of Sarbaz in Sistan-Baluchestan. The province is the scene of frequent clashes between security forces, Sunni rebels and drug traffickers.
The two high-ranking commanders were the deputy head of the Guards' ground forces, General Nourali Shoushtari, and the Guards' commander in Sistan-Baluchestan province, General Mohammadzadeh, news agencies reported. Shoushtari was also a senior official of the Guard's elite Qods force, media said.
Citing authorities and experts, a presenter of English-language Press TV said "the finger of accusation is directly pointed at the Jundollah group," referring to ethnic Baluch Sunni insurgents who have been blamed for previous attacks in the region, Reuters reported.