I've been informed that while the video that KSTP broadcast/posted didn't have any images of IAEA seals, they do in fact have footage, which should be coming out, of those seals. The seals mean that it was something nuclear or nuclear related, which the IAEA was monitoring (and would include the explosives in question)...
...and Garance reminds us that RDX has been used against the US at least 4 times.
...here's the footage of the seal.