Palestinian Prime Minister Ismail Haniyeh crossed into Gaza on Thursday, leaving behind money donated by Muslim states, hours after Israel blocked the Hamas leader from returning from a fund-raising tour with $35 million. The test of wills along the Egyptian frontier racheted up tensions in the Gaza Strip, where a political showdown between Hamas and the rival Fatah movement of moderate President Mahmoud Abbas has boiled over in recent days into a series of killings. Full Story