The IDF has developed a special training regimen to teach infantry units how to storm and sweep skyscrapers that have been built in the Gaza Strip and the West Bank. During Operation Cast Lead earlier this year, soldiers from the Givati Brigade took over two 15-story buildings in search of Hamas operatives in Gaza City's Tel el-Hawa neighborhood. The operation was the deepest push the IDF made into Gaza City and put soldiers just 500 meters away from the home of senior Hamas leader Mahmoud Zahar. The buildings were taken over by troops from the Givati Brigade's Reconnaissance Battalion. Some 40 Palestinian gunmen were reportedly killed during the maneuver - the kind of operation that is usually conducted by Special Forces due to its complexity. The storming of a multistory apartment building is particularly complicated due to the number of stairs soldiers need to climb - in some cases 800 - with all their equipment, as well as the need to sweep all of the apartments, sometimes five on each floor. "Sweeping tall buildings demands great physical stamina," a senior IDF officer explained on Tuesday. The IDF, the officer said, was working on formulating a set tactic for operations in large buildings. "The construction of these buildings in the Gaza Strip and the West Bank creates a need for this type of capability," he said.