According to material received from local authorities between April 1952 and March 1953, mostly from the local resistance committees (UBKCHC), the enemy launched:
- 42 attacks in Việt Bac, largely coming by airplanes, but using cannon and spies as well;
- 17-18 attacks in Liên Khu 3;
- 15-30 attacks in Khu Ta Ngan, with most coming in Februay 1953;
- and, scattered attacks elsewhere.
For a look at the attacks in different provinces in Việt Bac, see this map.
The enemy seemed to be spreading many things, including insects, but there were no witnesses that could tie them to airplanes and they existed in Vietnam already, so it was hard to say if they were introduced. The only solid evidence was for Cladosporium, which, the report argued, hadn’t existed in Vietnam before. It was unclear what were the effects, as Cladosporium didn't seem to harm humans, though it was noted that it could damage tomato plants.
The report noted that at first people in the delta were worried but that there had been no effects since 1952, so they were no longer as concerned and were no longer paying attention. The committee posed the question: Should the Việt Minh publicly denounce the plot of the enemy? The committee recommended that the Việt Minh wait to make a denunciation until the agricultural and medical institutes could make further investigations. The committee also developed several standardized forms that were supposed to provide a more rigorous report that could tie strange materials to enemy airplanes. See Form A, Form B (Page 1 and Page 2), and Form C (Page 1 and Page 2).