A radical Palestinian group that had agreed to a three-month halt in attacks against Israelis claimed responsibility today for a bomb blast Monday night that killed a 65-year-old Israeli woman in her home. The bombing, which came as other Palestinian militants threatened to continue attacking Israelis, suggested that internal opposition to the cease-fire is more intense and widespread than Palestinian leaders have acknowledged. In a further sign of widening rifts among Palestinian leaders, Prime Minister Mahmoud Abbas submitted his resignation today from the central committee of Fatah, the largest Palestinian political movement, in a dispute over his government’s relations with Israel. Full Story