WASHINGTON - The CIA used sophisticated new stealth drone aircraft to fly dozens of secret missions deep into Pakistani airspace and monitor the compound where Osama bin Laden was killed, The Washington Post reported Wednesday. Citing current and former U.S. officials, the newspaper said the unmanned planes, which are designed to evade radar detection and operate at high altitudes, conducted clandestine flights over the compound for months before the May 2 assault in an effort to capture high-resolution video that satellites could not provide. The aircraft, according to the Post, allowed the US spy agency to glide undetected beyond the boundaries that Pakistan has long imposed on other U.S. drones, including the Predators and Reapers that routinely carry out strikes against militants near the border with Afghanistan. Its not like you can just park a Predator overhead the Pakistanis would know, an unnamed former official was quoted as saying. The monitoring effort also involved satellites, eavesdropping equipment and CIA operatives based at a safe house in Abbottabad. The agency declined to comment on the story, the newspaper said. "The CIAs repeated secret incursions into Pakistans airspace underscore the level of distrust between the United States and a country often described as a key counterterrorism ally, and one that has received billions of dollars in U.S. aid," the dispatch said. The stealth drones provided imagery that President Barack Obama watched with his national security team as the nighttime raid unfolded, the Post said. The aircraft can also eavesdrop on electronic transmissions so that US official could listen in on Pakistan's response. Another stealth aircraft, a Black Hawk helicopter with specially designed cladding to dampen noise and avoid detection, was also used in the Abbottabad operation. But US forces destroyed it after a crash landing during the raid, leaving only a tail section behind. US officials noted that Predators and other non-stealth surveillance aircraft could have been detected by Pakistani radar and other systems at military and nuclear facilities near bin Laden's compound. The drones, which the Post suggested may have been Lockheed Martin's RQ-170 Sentinel model, can film at steep angles in all directions and so would not need to hover directly over their target.