The Israel Air Force used a new bunker-buster missile that it received recently from the United States in strikes against Hamas targets in the Gaza Strip on Saturday, The Jerusalem Post learned on Sunday. The missile, called GBU-39, was developed in recent years by the US as a small-diameter bomb for low-cost, high-precision and low collateral damage strikes. Israel received approval from Congress to purchase 1,000 units in September and defense officials said on Sunday that the first shipment had arrived earlier this month and was used successfully in penetrating underground Kassam launchers in the Gaza Strip during the heavy aerial bombardment of Hamas infrastructure on Saturday. It was also used in Sunday's bombing of tunnels in Rafah. The GPS-guided GBU-39 is said to be one of the most accurate bombs in the world. The 113-kg. bomb has the same penetration capabilities as a normal 900-kg. bomb, although it has only 22.7 kg. of explosives. At just 1.75 meters long, its small size increases the number of bombs an aircraft can carry and the number of targets it can attack in a sortie. Tests conducted in the US have proven that the bomb is capable of penetrating at least 90 cm. of steel-reinforced concrete. The GBU-39 can be used in adverse weather conditions and has a standoff range of more than 110 km. due to pop-out wings. Also Sunday, Military Intelligence's Psychological Warfare Department broke into radio broadcasts in Gaza and warned Palestinian civilians not to cooperate with Hamas terrorist activity. Palestinians reported that they received phone calls to their cellular phones and landlines from the IDF. The phone call, the Palestinians said, conveyed a recorded message ordering the immediate evacuation of homes that were next to Hamas infrastructure or being used by the terrorist organization. On Sunday, head of the Gaza Coordination and Liaison Administration Col. Moshe Levy was interviewed by several Arab news outlets during which he stressed that Israel was not against the Palestinian public in Gaza but was operating against Hamas. Defense officials said Sunday that Israel would, however, not hesitate to target the homes of civilians who protected Hamas terrorists throughout the operation. "We will go after every Hamas operative, no matter where he is," one official said. "We urge the Palestinians not to cooperate with terrorists."