Twenty nine sonic booms in 4 days is not a warning; it appears to be a collective punishment to the Gaza population. According to the 4th Geneva Convention (article 33): "Reprisals against protected persons and their property are prohibited". War crime charges can surface unexpectedly, as in the recent case of Israeli former OC Southern Command in Britain. And there is now also a recently established permanent international court against war crimes in the Hague. Gaza is still under occupation, since Israel controls all exits end entries, including those to Egypt (thru an agreement with the Egyptians). Notice that Egypt cannot even open the Raffah crossing on its own, as has become evident in recent days. Israel also controls the airspace (no aircraft other than IDF's are allowed), and territiorial waters of Gaza (where no vessel is allowed 5 km off shore). Warning is a good policy, but it is illegal to turn it into actual punishment. Open Gaza crossings (except to Israel itself), airspace and sea access. Then Israel can shut off electricity supplied by Israel, or apply sonic booms to its heart's content. But be careful of the commission of war crimes.
Hamas says Egyptian mediation has restored calm along Israel, Gaza border (Haaretz)
from the article: Demons in the skies of the Gaza Strip