"Cables that are part of a tunnel detection device are being installed along the Gaza-Egypt border," a security source said, adding the cables were being installed from south of Rafah to the Mediterranean coast.
The source said some cameras and sensors had already been installed, and the cameras would be connected by the cables.
For the 1.5 million people in the Gaza Strip, the tunnels have become a main source of goods, including fuel, since Israel tightened its embargo after Hamas seized control of Gaza from the forces of Palestinian President Mahmoud Abbas in 2007.
Israel bombed the tunnels during its recent 22-day Gaza offensive, and the Israel Defense Forces fears Hamas could use them to re-arm. But many tunnels have sophisticated systems and seem to have survived weeks of Israeli bombardment.
Roughly 1,300 Palestinians and 13 Israelis were killed in the Gaza offensive before both sides declared an end to the fighting on January 18. Israel says its offensive was aimed at halting Hamas rocket attacks on its southern communities.
Egypt, which has kept its Rafah border crossing with the territory largely closed, has agreed to help stop the tunnel smuggling with international technical assistance.
But no firm plan is yet in place as Israel and Hamas argue through Egyptian mediators about installing a longer term ceasefire that would meet Israel's demands for shutting off the arms supply and Hamas' demands for an easing of the blockade.
Egypt arrests politician for sneaking into Gaza
A security official says a former Egyptian opposition lawmaker has been arrested for allegedly using a smuggling tunnel to sneak into Gaza.
The official says Magdi Ahmed Hussein was arrested Saturday after showing up at the Egyptian-Gaza border crossing in Rafah without a passport. He says Hussein crossed into Gaza through an underground tunnel about two weeks ago.
The official spoke on condition of anonymity because he was not allowed to speak to the press.
Hussein is a banned Labor Party politician and former parliamentarian who has led several anti-government protests in the past. The party confirmed his arrest on its Web site but said Hussein traveled into Gaza through a hole in the border fence.