Khamenei says Iran will punish attackers

TEHRAN (Reuters) - Supreme Leader Ayatollah Ali Khamenei said on Monday Iran would punish those behind an attack on the Revolutionary Guards that killed 42 people and he suggested Western involvement in the incident.

"The mercenaries of the global arrogance should know that the Islamic system will strongly protect the region and defend its loyal people and will punish those who violate their lives and security," ISNA news agency quoted him as saying.

Iran, a predominantly Shi'ite Muslim state, usually refers to the United States when using the term "the global arrogance."

Guards commanders have accused the United States and Britain of backing the Sunni rebel group which Iranian media say has claimed the suicide bombing in southeastern Iran on Sunday, the deadliest such attack in Iran since its 1980s war with Iraq.

In his first public comment on the attack, Khamenei said the "enemies should know that they cannot harm the unity and solidarity (among Iranians) ... by such a criminal act," ISNA reported.

(Reporting by Hossein Jaseb and Reza Derakhshi; writing by Fredrik Dahl; editing by Jon Boyle)