Is there no better method to detect them. May be by digging and planting sensors in the earth that can pick up the sounds of the digging?

If the IDF finds the big politicians, I certain that they will find them hiding out very deep in a very heavily fortified bunker dug deep below the ground. It will have much provisions and equipment for them to stay safely for many months while the poor slobs in Gaza who live their and who major 'sin' was to have voted or supported Hamas live on top of the ground and get body piece blow up in their faces. To bad the people of Gaza are too stupid to see what their leaders have done to them for the sake of radical Islam. These poor folk have no where to hide and watch as their possessions are either stolen by their neighbors or blow up by the Israeli army.

How can any country live with this situation on its borders? Israel is being told: 'There is one option: you kill us or we kill you'. So goodbye, any hope of a Palestinian state. You could have had one, but now there can only be an Arab-free Israel from the Jordan to the sea.

The Hamas leadership is hiding in (or beneath) the Shifa Hospital, as reported by the Washington Post.

Remember when Israel would not allow concrete into Gaza, how the international community made Israel look bad, so Israel allowed in cement to rebuild civilian houses? The cement seems to have helped build terror tunnels as well!

From what I hear the very top leaders in Hamas are in Qatar, Egypt and Turkey on 'official business', to return when the peace is restored. Egypt brokered a ceasefire twice. Twice Israel accepted. Twice Hamas rejected. Their repeated refusal gave the IDF the signal to go on to the next stage.

I think some of the tunnels are lined with cement. Water is in short supply, and wouldn't do much against cement. Israel provides the electricity and water for Gaza, who owe about one billion shekalim in unpaid bills to Israel Electricity,

both above and underground.

You are correct. Qatar is the only Islamic country that openly supports Hamas, financially as well.

Gaza has underground cities where their leaders reside in war time! Well known fact.

Yeah,sure, you're sad the tunnels are being blown up. Cry us a river.