Palestinian police who lay siege to the West Bank's biggest refugee camp and battled Palestinian gunmen for more than 12 hours withdrew early Tuesday with two suspects in custody and a vow that security forces would no longer shy from entering terrorist strongholds. The operation, in which a policeman and eight passers-by were wounded by gunfire, was the first major offensive in Palestinian Authority President Mahmoud Abbas's campaign to assert control over gunmen and persuade Israel he can implement a future peace deal. For several years police had not dared patrol the four refugee camps in and around the city of Nablus or the old downtown market district, where armed militants held sway, but Nablus governor Jamal Mohsein said Tuesday that those days were now over. "We shall post police in all the camps and in the Old City," he said. "In future, nobody will be able to say that the police cannot go here or there."