Iran mum on U.S. claim of drone attack

An MQ-1 Predator unmanned aerial vehicle and F-16 Fighting Falcon return from an Operation Iraqi Freedom combat mission. Both aircraft provide intelligence, search and reconnaissance gathering features, as well as munitions capability to support ground troops and base defense. (U.S. Air Force photo/1st Lt. Shannon Collins) Iran has not acknowledged allegations that its fighter jets targeted a U.S. drone The Predator drone was fired on November 1 over international waters, the Pentagon says The drone was not damaged, and it was able to return to its base Washington (CNN) -- Iran remained mum Friday amid accusations that two of its warplanes opened fire on a U.S. Air Force drone over international waters, an incident that further heightens tensions between the two countries over Tehran's nuclear program. A day after CNN first reported the incident -- later publicly confirmed by the Pentagon -- neither Tehran nor its state-run media said anything about the incident that triggered a formal warning by the United States to Iran through diplomatic channels. The warning came after two Iranian Su-25 fighter jets fired on an unarmed Predator drone conducting routine surveillance in international airspace east of Kuwait, 16 miles off the coast of Iran, Pentagon Press Secretary George Little told reporters Thursday following CNN's report. Read more: U.S. targets Iranian human rights violators The Predator drone was not hit in the November 1 incident, and it returned under its own power to its base, he said. Little stopped short of calling the incident an act of war. "I'm not going to get into legal labels. The reality is that we have a wide range of options, as I said before, to protect our assets and our forces in the region and we'll do so when necessary," he said. "The United States has communicated to the Iranians that we will continue to conduct surveillance flights over international waters, over the Arabian Gulf, consistent with longstanding practices and our commitment to the security of the region." Little said warning was delivered through Swiss diplomats who act as on behalf of U.S. interests in Iran since Washington and Tehran cut ties in 1980. Read more: Unclear whether Iran shot down drone, a U.S. official says "Our aircraft was never in Iranian airspace. It was always flying in international air space. The recognized limit is 12 nautical miles off the coast, and we never entered the 12 nautical mile limit," he said. CNN has been unable to obtain a response from the Iranian Foreign Ministry. The Obama administration did not disclose the incident before the presidential election. Three senior officials confirmed the details of the incident to CNN on Thursday. The three spoke on condition of anonymity because of the sensitive intelligence nature of the matter. Two of the officials said the fighter jets belonged to Iran's Revolutionary Guard Corps force, which has been more confrontational than regular Iranian military forces. At least two bursts of gunfire came from the Su-25s' cannons, they said. The drone started to move away but the Iranian aircraft chased it, doing aerial loops around it before breaking away and returning to Iran. The drone's still and video cameras captured the incident, showing two Su-25s approaching the Predator and firing onboard guns, the officials said. The Iranian pilots continued to fire shots that went beneath the Predator but were never successful in hitting it, according to the officials. Iran has not addressed the allegations, and it is unclear from the description of events by Little whether the intention was to shoot the Predator down or just harass it. U.S. military intelligence analysts are still not sure if the Iranian pilots simply were unable to hit the drone due to lack of combat skill, or whether they deliberately were missing. "It doesn't matter, they fired on us," one official said. CNN's Chelsea J. Carter contributed to this report.