(IsraelNN.com) The de facto Hamas government in Gaza is exploiting Israel's allowing shipments of cement to build underground tunnels, ammunition bunkers and command centers. Deputy Defense Minister Matan Vilnai is thinking about reducing the amounts of cement, which began to flow through Gaza crossings in July.

The government allowed cement to cross into Gaza after Hamas reduced the number of rocket attacks on Israel.

Gaza residents complain about the small quantities of cement, but one of the reasons is that Hamas controls the distribution of humanitarian shipments and diverts much of them for their own use. It also controls the destination of goods transported through smuggling tunnels.

Hamas's underground city copies the system used by Hizbullah in the Second Lebanon War against Israel. IDF intelligence sources have told the Defense Ministry that an entire tunnel network has been built underneath major cities in Gaza to allow the Hamas terrorists army to move freely in the event of an Israeli invasion.

Many of the tunnels are filled with explosives that can be detonated by remote control devices and cause the collapse of roads over which IDF convoys might use.

Hundreds of Katyusha and Kassam rocket launchers also have been placed underground, safe from aerial attack, the Hebrew newspaper Ma'ariv reported.

Arab and Western media published dozens of articles earlier this year, blaming the Israeli "siege" on Gaza for causing shortages of cement, and preventing new construction and even the erection of new gravestones.