Twin suicide bombings outside a prominent Shi'ite mosque in southeastern Iran have killed at least 22 people, including worshippers and members of the country's powerful Revolutionary Guard.
The attacks late Thursday wounded more than 100 others at the main mosque in Zahedan, the capital of Sistan-Baluchistan province, and came as Shi'ites celebrated the birthday of the Prophet Muhammad's grandson, Imam Hussein. The day is also set aside each year to honor the Revolutionary Guards.
Iranian officials have said they will continue investigations, though the Sunni Muslim militant group Jundallah claimed responsibility for the bombings on its website. The group said it had carried them out in retaliation for Iran's execution in June of the group's leader, Abdolmalek Rigi. Iran had convicted the militant leader of terrorism.
U.S. Secretary of State Hillary Clinton condemned the attacks Thursday. She noted the violence underscored the need for the global community to continue to fight terrorism.
Jundallah said the bombings were carried out by relatives of Rigi (Mohammad Rigi and Abdulbaset Rigi) and warned of more explosions to come.
Sistan-Baluchistan province, an impoverished area bordering Pakistan, is the base for an insurgency led by the Sunni militant group. Shi'ites in the province, home to a large Sunni Baluch minority, have been the target of numerous attacks.
Jundllah, or Soldiers of God, said it carried out a similar mosque attack two months ago that killed 25 people in Zahedan. The group also claimed responsibility for a bomb attack last October that killed 57 people, including several top Revolutionary Guard commanders.
Jundallah members say they are fighting to secure rights for the Sunni Baluchis in Shi'ite-dominated Iran. Deputy Interior Minister Ali Abdollahi told the semiofficial Fars news agency Thursday's incident was a terrorist act.
Abdolmalek Rigi was detained in February by Iranian intelligence on a flight from Dubai to Kyrgyzstan. He was later charged with 79 counts of armed robbery, kidnapping, bombing operations and being the founder and leader of Jundallah. The militant leader's younger brother, Abdolhamid Rigi, was executed by hanging in Zahedan two months ago.
Iran has accused the United States of funding Jundallah militants in an effort to destabilize the Iranian government. Iran says Jundallah is based in Pakistan. The U.S., Britain and Pakistan all have denied backing Jundallah.
Some information for this report was provided by Reuters.