TEL AVIV, Israel -- The Israeli Defense Force says 31 tunnels have been discovered since invading Gaza two weeks ago.
Hamas has built a maze of interconnected tunnels, thought to number in the hundreds, underneath Gaza to get around tight Israeli security. Some are big enough to drive a truck through.
Former head of Israeli military intelligence Amos Yadlin explains, "There are like two or three entrances. There are rooms and bunkers to keep supplies, explosives. So it is a whole system. Very much like the streets of New York City under the ground."
To avoid detection, the tunnels are dug sixty feet beneath the surface. Hamas claims they are Gaza's economic lifeline, the only way to get much needed supplies and essentials. The IDF says the tunnels are used by militants to smuggle weapons and explosives, and to launch raids.
Last Sunday, the IDF says it spotted ten Hamas militants near a tunnel about an hour from Tel Aviv. An Israeli helicopter fired on them.
Micha Ben-Hillel says he has lived here for almost fifty years. He was asleep in his house nearby when the gunfire woke him up.
"Israel cannot allow this situation. I mean, no country would allow such a situation. When people can cross the border for the purpose of killing and murdering," says Ben-Hillel.
Even when discovered, tunnels are difficult to destroy. They are often hundreds of feet long, so just blowing up the openings doesn't mean they can't be used again.
This latest incident bring the death toll in Gaza to nearly 800 with 35 Israelis having lost their lives, 32 of them are soldiers.
Israel is saying it will continue until the tunnels are gone.