Iranian police and insurgents clashed briefly after a bomb - described as "sound bomb" - went off in southeastern Iran but injured no one, the country's state-run news agency said on Saturday.
The device exploded late Friday near the site where an earlier explosion this week killed 11 members of Iran's elite Revolutionary Guards in Zahedan, the capital of the Sistan-Baluchestan province on the border with Pakistan.
"The explosion left no casualties or injuries and didn't cause damages," Hasan Ali Nouri, governor of Zahedan, was quoted as saying by the official Islamic Republic News Agency.
IRNA said police and insurgents briefly clashed after the explosion at a school in Zahedan. No one was in the school at the time of the blast.