Defense Minister Ehud Barak rebuffed a call Wednesdayby UN Secretary General Ban Ki-moon to allow humanitarian aid into Gaza after Israel was forced to shut down the border crossings and halt supplies due to the constant barrages of rocket attacks on southern Israel. On Monday Israe permitted 33 truckloads of supplies to enter Gaza despite the attacks.The Palestinian Authority meanwhile accused Hamas of staging power cuts in the narrow strip in a bid to win sympathy and incite the Palestinian public against Israel and the PA. The officials said that contrary to Hamas's claim, there is no shortage of basic goods, medicine and fuel in the Gaza Strip, largely thanks to the many underground tunnels along