The Sunni Muslim rebel group Jundollah said it was behind twin suicide bombings in Iran which killed at least 21 people on Thursday, including members of the elite Revolutionary Guards, Al Arabiya television said.

The group said the attacks were a response to the execution by Iran of its leader Abdolmalek Rigi in June, the Dubai-based channel said.

In an email to the station the Jundollah said that the bombings were carried out by two relatives of Rigi, and were aimed at a gathering of the Revolutionary Guards in Zahedan, Arabiya said.

'The group said the suicide attacks were carried out by Abdolbaset Rigi and Mohammad Rigi and warned of more operations to come,' the television added.

Predominantly Shi'ite Muslim Iran arrested Rigi in February, four months after Jundollah claimed a bombing which killed dozens of people, including 15 members of the Guards. It was the deadliest attack in Iran since the 1980s.

Iran has linked Jundollah to the Sunni Islamist al Qaeda network. It also accuses the US of backing Jundollah in order to create instability in the country. Washington denies the charge.

Jundollah denies having any links to al Qaeda and says it is fighting for the rights of Iran's minority Sunnis. Iran rejects allegations by rights groups that it discriminates against ethnic and religious minorities.-Reuters