Iranian state-run media reported Monday that the country had arrested members of an espionage network with ties to the Mossad. Monday's announcement came two days after government officials announced that Iranian businessman Ali Ashtari, who had been convicted of spying for Israel in June, was hanged last week. "The security and intelligence division of the Islamic Revolutionary Guards Corps (IRGC) recently identified a network that was spying on the country's military organizations," the Fars news agency on Monday quoted the IRGC chief commander Brig.-Gen. Muhammad-Ali Jafari as saying, according to the Iranian government-owned Press TV. "The network's link with Mossad was established after extensive intelligence and tracking operations. Members of the cell were arrested during an operation," he said. In Jerusalem, the Prime Minister's Office declined to comment on the reports. Prime Minister Ehud Olmert was in the United States for a farewell visit to outgoing US President George W. Bush, although government officials often do not comment on such reports. Jafari also said in a state radio report on Monday that the alleged network had been trying to gather information on Iran's nuclear program, the Guards' military operations and on military and security officials. Jafari also said that equipment belonging to the alleged network had been confiscated, but didn't provide details on how many people had been arrested or exactly when. The arrests, along with last week's execution, indicate that Teheran fears foreign activity in the country as well as potential military action on Iran's nuclear installations, said Menashe Amir, an Iranian affairs expert and chief editor of the Israeli Foreign Ministry's Persian Web site. The arrests also served as a warning to Iranian citizens opposed to Iran acquiring nuclear weapons not to cooperate with foreign powers, he said. Teheran also wanted to show its enemies that it "will not remain silent about any espionage activities," he added. The arrests might also be part of the confrontations between different political camps inside Iran "to silence opposition groups inside the regime itself," Amir said. Presidential elections are scheduled to be held in about 10 months. Iran has released "a barrage of press announcements" in recent months, and particularly in the last week, concerning arrests it had made for alleged espionage or related activities, Amir said. On November 18, for example, the Iranian Jahan news Web site reported that the prolific internet blogger Hossein Derakhshan - who was affiliated with an opposition group - had been arrested in Teheran and was being investigated on suspicion of spying for Israel. In January 2006, the self-exiled Iranian, who has long lived abroad, visited Israel as a Canadian citizen and blogged about his trip. In another incident, about two weeks ago Iranian TV and radio stations quoted an anonymous military source as saying that 10 spies had been arrested illegally crossing the Pakistan-Iran border. The "spies" had reportedly been carrying half a million dollars with them in addition to espionage equipment. Two days later, however, the government said the information was incorrect, Amir said. Three people also recently confessed to involvement in a deadly bombing of a mosque in the city of Shiraz in April, Reuters reported on Saturday, citing state media. Officials in Teheran, who at first said the explosion was an accident, have said that the United States, Britain and Israel were involved in the incident, which reportedly killed 14 and wounded 200. Meanwhile, an Iranian militia held civil defense drills on Sunday to prepare for any air strikes and the country's military officials said they could close the Straits of Hormuz, a crucial waterway for world oil supplies, if Iran was attacked, Reuters reported. AP contributed to this report.