The IDF was gearing up on Sunday for a wave of Hamas attacks along the Gaza border after the terror group carried out an ambitious large-scale attack against the Kerem Shalom crossing with Israel a day earlier. Thirteen soldiers were wounded at 6 a.m. on Saturday when an armored personnel carrier - supplied to the Palestinian Authority in the 1990s - rammed through the fence between Israel and southern Gaza near the Kerem Shalom crossing, used to transfer humanitarian aid to the Strip. After the APC opened the gate, two vehicles - disguised as IDF jeeps and packed with 300 kilograms of explosives each - drove through. One blew up next to an IDF watchtower, causing extensive damage but no injuries to the soldiers inside. The second vehicle exploded next to a number of IDF jeeps belonging to the Southern Command's Beduin Desert Battalion. Despite the thick fog, the deputy battalion commander spotted the second jeep as it made its way into the crossing. Thinking at first that the jeep was Israeli, the officer tried to contact the driver on the standard military radio frequency. When he did not receive an answer, he understood that it was a car bomb. "The deputy battalion commander shouted, 'Car bomb, car bomb,' and all the soldiers ran into their armored jeeps," an officer who witnessed the infiltration said Sunday. Most of the soldiers made it into the vehicles. The 13 who didn't sustained light-to-moderate wounds. Moments later, another APC approached the Kissufim crossing, north of Kerem Shalom. A tank from Brigade 401 opened fire and destroyed the vehicle, which was believed to have been packed with explosives. In response to the attack, Israel carried out a number of air strikes against Hamas targets in Gaza, killing seven Palestinians. Two others were killed during the attack against Kerem Shalom. "This was a series of attacks aimed at killing and kidnapping soldiers," OC Southern Command Maj.-Gen. Yoav Galant said on Saturday. "This is an attack the likes of which we have not seen since the disengagement [in 2005]." Defense Minister Ehud Barak said Hamas and its leaders bore direct responsibility for the attack. During a tour of the crossing with IDF Chief of General Staff Lt.-Gen. Gabi Ashkenazi, Barak expressed appreciation for the Beduin Desert Battalion, whose deputy commander's quick response prevented a "strategic terror attack." Defense officials said Kerem Shalom would remain closed for at least two days, and until all of the breaches in the security fence were sealed. Officials said that while the army responded quickly to the infiltration, there might be a need to rethink the security arrangements at the crossing, which allowed the Palestinian APC to ram the fence without being intercepted. IDF sources said that a probe had been launched to thoroughly study the attack and recommend improvements that could be made to the army's deployment in the area. Hamas said the attack was part of a campaign to break the nearly year-long blockade of Gaza. Senior Hamas official Sami Abu Zuhri warned that the crossings would be targeted again. Saturday's attacks "are the beginning of the explosions that Hamas has warned of," he said. "If the parties don't intervene quickly to save Gaza and break the siege, what is coming will be greater." Also on Sunday, defense officials said Israel did not plan to alter an earlier decision to permit the PA in the West Bank to receive 25 APCs from Russia, despite the use of an armored vehicle in the Kerem Shalom attack. The decision to transfer the APCs was made by Prime Minister Ehud Olmert several months ago following a request by Russia to supply the vehicles to Fatah forces in the West Bank to bolster PA President Mahmoud Abbas. Meanwhile, the IDF decided Sunday to investigate the death of Fadel Shana, the Reuters cameraman killed in Gaza by Israeli tank fire on Wednesday. The New York-based group Human Rights Watch said its investigation suggested soldiers either fired recklessly or targeted Shana. The IDF announced that its investigation would be reviewed by the military advocate-general.