A suicide bomber killed at least 20 people on Sunday, including five senior commanders of Iran's elite Revolutionary Guard, in southeastern Iran, the country's official news agency reported.
The IRNA news agency said the dead included the deputy commander of the Guard's ground force, Gen. Noor Ali Shooshtari, as well as the Guard's chief provincial commander, Rajab Ali Mohammadzadeh. Dozens of others were wounded, the report said.
The commanders were inside a car on their way to a meeting in the Pishin region near Iran's border with Pakistan when an attacker with explosives blew himself up, IRNA said.
Iran's parliamentary speaker, Ali Larijani, condemned the assassination of the Guard commanders, saying the bombing was aimed at disrupting security in southeastern Iran.
``We express our condolences for their martyrdom. ... The intention of the terrorists was definitely to disrupt security in Sistan-Baluchistan Province,'' Larijani told an open session of the parliament broadcast live on state radio.
There was no immediate claim of responsibility, but suspicion would likely fall on the Sunni militant group Jundallah, or Soldiers of God, which has carried out attacks in southeastern Iran against Shia targets.
In May, the group took credit for a suicide bombing at a Shia mosque that killed 25 people in Zahedan, the capital of Iran's Sistan-Baluchistan province, which has witnessed some of Jundallah's worst attacks. Thirteen members of the faction were convicted in the attack and hanged in July.
Jundallah, comprising Sunnis from the Baluchi ethnic minority, have waged a low-level insurgency in recent years, accusing the mostly Shia government of persecution.
Jundallah has carried out bombings, kidnappings and other attacks against Iranian soldiers and other forces in recent years, including a car bombing in February 2007 that killed 11 members of the Revolutionary Guard near Zahedan.
Jundallah also claimed responsibility for the December 2006 kidnapping of seven Iranian soldiers in the Zahedan area. It threatened to kill them unless members of the group in Iranian prisons were released. The seven were released a month later, apparently after negotiations through tribal mediators.