Egyptian security reports  (Arabic link) revealed that Hamas is spending $140 million a year to dig terror tunnels. According to the reports, no less than 12,000 Palestinians, many of them children, take part in the process of building the tunnels.
These tunnels are used to smuggle weapons and materials used to manufacture explosive devices, as well as transferring terrorists between Gaza and the Sinai. According to the Al-Arabiya news website , Hamas has set up a special tunnel-digging unit under the control of the movement’s paramilitary group, the Izz al-Din al-Qassam Brigades.
Egyptian security sources revealed that another special division belonging to Al-Qassam Brigades provides each tunnel with tons of cement so that it does not collapse. The entrances of the tunnels are excavated inside homes, mosques, and schools to prevent their exposure.
A Palestinian official said that each tunnel excavation takes several months. The cost of construction of an average tunnel reaches $100,000 dollars.
Earlier this year, Jonathan Halevi of the Jerusalem Center for Public Affairs described  the strategic threat of Hamas terror tunnels:
The attack tunnels create a new equation in the power balance between Israel and Hamas. They give Hamas an ability to infiltrate Israel and carry out strategic attacks involving mass killing, along with an ability to launch missiles from locations concealed within civilian population centers that serve, in effect, as human shields. Should Hamas retain in the future 20 tunnels, and dispatch 50 operatives in each, they could deploy 1,000 men behind Israeli lines. The tunnels would allow Hamas to wreak havoc if they are left in place.
[Photo: Zoriah / Flickr ]