TEHERAN: A provincial official said on Friday those behind a mosque bombing that killed 20 people in Iran had been hired by the United States, Teheran's arch-foe, a semi-official news agency reported.

Jalal Sayyah, at the governor's office in Sistan-Baluchestan province, said three people had been arrested in connection with Thursday evening's blast in a crowded mosque in the southeastern city of Zahedan, near Pakistan.

The explosion, which some Iranian news agencies say may have been a suicide bombing, took place on a religious holiday two weeks before the June 12 presidential elections. More than 80 people were wounded.