After a lull of nearly three months, serious fighting broke out this week between Hamas and Fatah militants. Hamas gunmen attacked a unit of President Mahmoud Abbas presidential guards, killing at least eight. At least 10 more people, mostly Fatah members, were killed in other clashes. Islamist Hamas and secular Fatah formed a unity government two months ago, but they have continued to jockey for power. In a blow to the unity government, Interior Minister Hani alQawasmi, an independent, resigned in protest over his lack of resources to stop the fighting.