IAF aircraft struck in the northern Gaza Strip on Sunday after a rocket attack on southern Israel, the military said, and three unidentified Palestinians were killed. Witnesses said an Israeli missile struck a trailer near the town of Beit Lahiya. Palestinian hospital officials said three Palestinian civilians were killed, and identified them as Zaher al Aaer, 40, his 18-year-old son, Youssef, and a neighbor, Mohammed Abu Herbet, 23. The IDF said it targeted a rocket squad that attacked southern Israel earlier in the morning, but had no information on casualties. No one was hurt in that rocket attack or two others that took place early Sunday, an army spokesman said. More than a dozen mortar shells were fired at western Negev communities during Shabbat, while a Lebanese newspaper reported that Israel has been given a diplomatic "green light" for a large military operation in the Gaza Strip. No damage was reported from the strikes, even though three of the 13 shells struck towns or villages. The Lebanese newspaper Al-Akhbar reported Saturday morning that "credible diplomatic sources" had said American approval for a broad operation in Gaza had come after Israeli intelligence impressed on US officials the importance of such an incursion as an answer to the unprecedented level of arms smuggling to Gaza from Sinai. IDF combat engineers and infantrymen from the Golani Brigade have been operating on the Gaza-Egyptian border since last week to locate and destroy the tunnels used by weapons smugglers. Tunnels were found as close as two kilometers from the border with Israel and were destroyed in controlled explosions. IDF sources said they were most probably used by terrorists to leave Gaza on their way to Iran or Syria for training. According to the newspaper report, the Israeli intelligence was shared during Defense Minister Ehud Barak's last visit to Washington. Sources told Al-Akhbar the reports painted a worrying picture of an "arms race" between Hamas and Islamic Jihad. Israel also presented details of money transfers between Islamic Jihad and Fatah's Aksa Martyrs Brigades. Over the past few days, Barak has met a number of times with Prime Minister Ehud Olmert to definitively fix the timing of a wide-scale military operation, Al-Akhbar cited the sources as saying. The sources added that despite the "green light," Israel was hesitant to launch an operation out of concern that it would complicate preparations for the upcoming US-sponsored Middle East peace conference in Annapolis, Maryland. Meanwhile, IDF units on the Gaza border will continue training for a massive operation in the Strip, the report said. Following four Gazan rocket attacks on Friday, a Hamas member was killed and three others were wounded in an IAF strike on a Hamas outpost in response to mortar fire on southern Israel. The army said it struck the Hamas position following repeated rocket and mortar fire from Gaza. Hamas confirmed that one of its men was killed in the attack near the former settlement of Morag in southern Gaza. In the West Bank overnight Friday, a bomb was detonated near IDF forces and, in a separate incident, shots were fired at soldiers in Tulkarm. None of the soldiers were wounded.