DUBAI—An electrical power problem caused an incident at Iran’s Natanz underground nuclear facility on Sunday, Iranian Press TV reported, a day after Tehran launched new advanced uranium enrichment centrifuges at the site. “The incident caused no casualties or contamination,” Iran’s Atomic Energy Organization spokesman Behrouz Kamalvandi said, adding that “electricity was affected at the Natanz facility,” which is located in the desert in the central province of Isfahan. The underground Natanz site is the centrepiece of the Iranian regime’s uranium enrichment programme and monitored by inspectors of the International Atomic Energy Agency, the U.N. nuclear watchdog. “The cause of this incident is under investigation,” Kamalvandi told Iran’s semi-official Fars news agency. In July last year, a fire broke out at the Natanz facility, which the regime said was an attempt to sabotage Iran’s nuclear programme. In 2010, the Stuxnet computer virus, widely believed to have been developed by the United …