QUANTICO, Va. (CNN) — The FBI investigation into the recovered Chinese spy balloon is the first of its kind in the bureau's history, senior FBI officials familiar with the operation said Thursday as they described the initial stages and what's been recovered so far.
The officials said that this is the first time the FBI has investigated a spy balloon of this nature and assisted with the processing of such a scene. The officials added that understanding the components of the balloon is vital intelligence and could be "important pieces of evidence for future criminal charges that could be brought."
The parts of the balloon recovered on the surface of the ocean have been delivered so far, while recovering additional pieces of the balloon that sunk has been complicated by bad weather, officials said.
It's not yet clear where the balloon's parts were manufactured, the officials said, including whether any of the pieces were made in America. Because analysts have yet to look at the bulk of the equipment on the balloon, the officials said that there has not been a determination as to everything the device was capable of doing and its specific intent.
Of the small portion they have examined, analysts have not identified any sort of explosive or "offensive material" that would pose a danger to the American public.
The FBI was alerted to the balloon on February 1, the officials said, because the intelligence community had determined that the balloon had an electronic element to it. By late Sunday -- the day after the balloon was shot down -- agents had arrived at the scene, and the first pieces of recovered evidence arrived at the FBI lab in Quantico on Monday.
There was English writing on parts of the balloon that were found, one of the sources familiar with the congressional briefings said, though they were not high-tech components. The source declined to provide detail on what specific parts of the balloon contained English writing.
Bloomberg News first reported that components of the balloon had English writing on them.
