The IDF struck 50 targets throughout the Gaza Strip late Monday night and early on Tuesday, marking the start of Operation Protective Edge, launched to extinguish Hamas rocket fire on Israel. Forty seven targets were hit by Israel Air Force aircraft, and an additional three were hit by Israel Navy ships off the coast of Gaza. "We are entering into a long operation," a senior IDF source said. "We are only at the start. Patience is required. We are preparing further steps and a gradual expansion of our order of battle," the source said, referring to a growing presence of Ground Forces deployed to the Gaza Border. The operation is being led by the IDF's Southern Command. During the overnight strikes, the IDF hit 18 underground rocket launchers, dozens of homes belonging to Hamas members, three Hamas command and control facilities, and then targets described by the source as "infrastructure." Most of the air strikes targeted Hamas, though some targeted other terror groups that have been involved in recent projectile fire on Israel. The IDF is currently gathering intelligence ahead of its next wave of strikes, according to the source. In recent hours, Hamas fired rockets at Kiryat Malachi, and at Kibbutz Ein Hashlosha in the Eshkol region. "We are preparing to add to our two special infantry formations that are on the Gaza border, and which are now busy with efforts against [cross-border] attack tunnels," the source said. "We have fully deployed Iron Dome batteries. And we are moving towards a significant phase of the operation, in terms of attacks on targets," he added. IDF Chief of Staff Lt.-Gen. Benny Gantz has begun a series of security evaluations on Tuesday. On Monday evening, he gave final approval for an operation based on a phased increase of attacks on Hamas.Hamas initiated this round of fighting to try and alleviate the distress it has found itself in recent months, the source said. In the West Bank, its position has been damaged by the army's response to the kidnap and murder of three Israeli youths in June, which resulted in the arrest of hundreds of Hamas members, raids on weapons caches, and against its civilian and economic networks.In Gaza too, it is feeling increased pressure, the source stated. As a result, Hamas is currently "seeking an accomplishment," the source said. "Hamas had high expectations two months ago. It had just joined a Palestinian unity government [with Fatah]. Now, it finds itself in a poor situation. It's gotten poor results from the kidnapping, its position in terms of Palestinian security prisoners has worsened [due to the arrest of hundreds of Hamas members last month], and its sovereignty in Gaza has sustained blows," he continued. "Hamas is under pressure, and this has caused it to begin shooting. It's status among the public [in Gaza] is also problematic. In the middle of Ramadan, it has no good news to offer Palestinians recently," the source said. Hamas has been directly and indirectly orchestrating the growing rocket salvos from Gaza, which reached a peak on Monday night, when many dozens of rockets were launched within an hour. "Hamas will always want to be the one that fires the last rocket, and to be able to claim that Israel is deterred. On the other side, Israel will gradually increase the scope of the operation, to obtain deterrence and damage Hamas," the source warned.