(Adds Jundollah claims responsibility, paragraphs 2, 9-10) By Edmund Blair TEHRAN, Feb 14 (Reuters) - A booby-trapped car blew up a bus owned by the Revolutionary Guards on Wednesday, killing at least 11 people, in a border city in southeastern Iran where security forces and drug smugglers often clash, state media reported. Jundollah (God's soldiers), a shadowy Sunni Muslim group that Iran has linked to al Qaeda, claimed responsibility, an Iranian news agency and a Dubai-based TV channel said. The group has been blamed for past kidnappings and killings in the area. Clerics were quick to urge Iranians, who are overwhelmingly Shi'ites, not to blame Sunnis for the incident. Iran is wary of anything that might spark sectarian tension in a country where Sunnis make up about 9 percent of the 70 million population. Provincial governor Hassan Ali Nouri told the official IRNA news agency 11 staff members of the Guards were killed and 31 injured in the blast in Zahedan city in Sistan-Baluchistan province, which is on the border with Pakistan and Afghanistan. The governor said one of those behind the blast was killed in the incident, suggesting a total toll of 12, but he did not spell this out. IRNA earlier said 18 people were killed, while state TV and radio said the death toll was 11. The bomb was hidden in a car and exploded at about 6.30 a.m. (0300 GMT) as the bus, belonging to a unit that transports employees of the Guards, passed by, IRNA said. Pictures showed the wreckage of a bus at the side of the road. "Five people have been arrested," an official in the governor's office of Zahedan told Reuters. Fars news agency said four people were in the car which seemed to have broken down on the road. When the bus approached, the four fled on motorbikes and the car exploded. "A group called Jundollah, under the leadership of Abdolmalek Rigi, the eastern rebels in the country, ... took responsibility for this terrorist act," Fars said. Dubai-based Al Arabiya television also said a caller speaking for Jundollah said the group was behind the attack. "ALL MOURN AND WORRY" Iran has said Jundollah was behind the murder of 12 people in a roadside attack in May, and other incidents. Officials previously said Rigi was a cell leader of Osama bin Laden's al Qaeda network in Iran. IRNA quoted an unnamed official as saying evidence suggested the group had support from Iran's arch-foe, the United States. Iran often accuses Washington of stoking tension. "People should face this crime with patience, awareness and realism just like other events and separate the issue of a few rebels from Sunnis -- though they were Sunnis -- because our Sunni brothers are innocent of these crimes," said Abbasali Soleimani, who represents Iran's supreme leader in the area. Soleimani, who was quoted by IRNA, said "enemies" had crossed into Iran to carry out the attack. Iraq, on Iran's western border, is riven by Sunni-Shi'ite tensions. Sunni regions in Iran, like Sistan-Baluchistan, say they suffer discrimination in the Islamic Republic. Supreme Leader Ayatollah Ali Khamenei, in response to fighting in Iraq, has also warned Iranians about what he says are U.S. efforts to divide the two Muslim sects. The area around Zahedan resembles a war zone, dotted with forts, trenches and machinegun posts. More than 3,300 Iranian security personnel have died in the region fighting drug traffickers since the 1979 Islamic revolution. (Additional reporting by Dubai bureau)
