In 2006, during the Second Lebanon War, a small team of soldiers from the Engineering Corps's elite Yahalom Unit crossed into southern Lebanon, and began clearing roads of Hizbullah-planted mines and bombs. They performed a similar feat in January, during Operation Cast Lead in the Gaza Strip. After the decision was made to launch a massive ground offensive, it was the soldiers from Yahalom who were the first to cross into the Hamas-controlled territory to pave the way for IDF infantry forces and columns of Merkava tanks. Sources in Yahalom say that the unit encountered thousands of explosive devices inside Gaza during the nearly three-week-long operation. These "Improvised Explosive Devices" (IED) were of varying types and deployed almost everywhere. Some were mines, buried underground and set to detonate as tanks or armored personnel vehicles passed above. Others were hidden in satellite dishes, stairwells, chicken coops, schools, zoos and mosques. And soldiers even discovered medicine bottles converted into grenades. "There were so many explosive devices that when bomb-sniffing dogs from the Oketz Unit got out of the vehicles, they would sit down in the middle of the street, signaling that explosives were nearby," an officer in the unit told The Jerusalem Post. "The dogs didn't even have to get next to the homes, since bombs were everywhere." For example, one officer recalls that, during the second week of the ground offensive, a team surrounded a mosque in the Shati refugee and discovered three bombs outside - hidden under clothing - connected to a wireless detonator. "Inside the mosque, several bombs were lying on the staircase, as if on display in a museum." YAHALOM - HEBREW for "diamond" - was established in 1995. It was created through the consolidation of two preexisting units of the Engineering Corps: Yael, responsible for maritime sabotage and obstacle breaching; and Yasap, an acronym for the Bomb Disposal Unit. Considered one of the IDF's top units, Yahalom reportedly operates regularly with the military's special forces. Its soldiers are experts in bomb disposal and controlled detonation. If a building collapses in Gaza, and it is not the result of a terrorist "work accident," it is likely to be the handiwork of Yahalom. IN THE 14 years since its establishment, Yahalom has added a number of sub-units, each with a different specialty, to its core. One of these, which specializes in breaching buildings, was created following the failed 1994 attempt to rescue kidnapped soldier Nachshon Wachsman. During that rescue attempt, it took the soldiers from the General Staff Reconnaissance Unit (Sayeret Matkal) too much time to break down the door. As a result, the terrorists holding Wachsman realized they were being attacked, and had time to kill the abducted soldier. Another sub-unit, about which little is known, is "Givol." All that can be written about it here is that it was established following the 9/11 attacks in the United States, and specializes in non-conventional threats. The last sub-unit - and possibly the most important, considering today's theater of operations in Gaza - is called "Samur," which is Hebrew for "weasel." Samur's specialty is locating and destroying smuggling tunnels and hidden weapons caches. During Operation Cast Lead, this sub-unit worked overtime. And its officers say they were not surprised by the amount of explosives they encountered in Gaza, but rather their points of origin - which, according to IDF intelligence, included Sudan, Eritrea, Somalia, Iran and Syria. "It was really like the movie Lord of War," the officer said, referring to the 2005 Hollywood film in which Nicholas Cage plays an international arms dealer. YAHALOM SUFFERED a blow on January 6, when one of its bomb-disposal experts, Alexander Mashevizky, was killed in a gun battle with Hamas operatives in a neighborhood north of Gaza City. At a rare press conference following the clash, the unit's commander, Lt.-Col. Amir, said that Yahalom was operating with unprecedented force against Hamas. "We are very aggressive," he said. "We do not hesitate to use different methods in order to preserve the troops on the ground. We are hitting an enemy who wants to strike at us." THOUGH, IN the end, 10 soldiers were killed during Operation Cast Lead, the IDF had prepared for many more casualties (initial death-toll estimates had been of a 10:1 ratio - one Israeli per every 10 Palestinians). The consensus among the top IDF ranks is that Yahalom's role was instrumental in this estimate's having proved false. As a result, the IDF Ground Forces Command is currently considering adding a new battalion to the existing three Combat Engineering ones, as well as expanding and beefing up Yahalom with additional soldiers and resources. "The fact that forces were able to arrive at their destination without casualties means that we succeeded," OC Engineering Corps Brig.-Gen. Shelly Moshe told the Post. In addition to expanding the corps, Moshe has also recommended purchasing an additional number of unmanned D9 bulldozers, which provided exceptional results during the Gaza operation. One of these, the Black Thunder, looks like a regular D9 bulldozer, but is equipped with cameras that transmit images to the operator of the vehicle, who controls it with a wireless remote control. Other robots were also used during the operation, such as the Eyedrive, a four-wheel observation-and-surveillance, remote-controlled, lightweight mini-robot that provides continuous, real-time, 360Â° audio-and-video surveillance. Due to its durability, this robot can be thrown on the ground, descend stairs, flip over and keep on going. Yahalom uses a wide variety of robots for its operations - to dismantle bombs, survey tunnels and scan houses before entering. Moshe says that plans are underway to distribute small robots to every infantry battalion in the IDF. Moshe said that what surprised him during the operation was not the number of IEDs or tunnels, but " how low Hamas was willing to go" in its "cynical use" of civilian infrastructure. ONE OF Yahalom's greater challenges is the 14-kilometer Philadelphi Corridor, where prior to Operation Cast Lead there were believed to be several hundred active smuggling tunnels. Though not in control of the Corridor, the IDF may have to operate there in the future. And it will be up to Yahalom to discover and destroy the tunnels. Still, despite years of testing, neither the IDF nor any other military in the world has come up with a perfect detection system. "We have the most advanced technology, " Moshe said. "But it has yet to fill the gap and meet the operational needs of such a huge challenge."