Palestinian police who lay siege to the West Bank's biggest refugee camp and battled Palestinian militants 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 militant strongholds. The operation, in which a policeman and eight passers-by were wounded by gunfire, was the first major offensive in President 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." Police marksmen took up positions on rooftops on the edges of the Balata refugee camp, adjoining Nablus, and traded shots with gunmen from the Al Aksa Martyrs' Brigades, a violent offshoot of Abbas's Fatah movement. After midnight two Al Aksa fighters armed with assault rifles surrendered to police and the operation was wound down. During the offensive the streets of the camp were littered with rocks and overturned trash containers - a scene reminiscent of past IDF army raids. Residents watched from their balconies. Near a mosque, police peeked around a corner, then fired down a narrow street. Operatives had vowed to resist a police presence in Balata. "They are trying to enter the camp and we will not let them," Nasser Abu Aziz, an Al Aksa gunman, said in a telephone interview. "I'm in the middle of shooting, I can't talk much," he said, before hanging up. Ziad al-Ali, a Palestinian security chief, said the Al Aksa Brigades must disband, noting that nearly all the group's members have accepted an amnesty deal with Israel, brokered by Abbas, in which they agreed to disarm. Monday's confrontation began after police seized a pistol from an Al Aksa member, and two of his friends then opened fire on the security forces. Some Al Aksa gunmen have balked at handing over their weapons as part of the deal with Israel. During the second Palestinian uprising, which erupted in 2000, Nablus and Balata became increasingly lawless, and some gunmen involved in fighting Israeli soldiers also blackmailed and robbed local residents. Last week, Abbas sent 300 extra policemen to Nablus, turning the city into a test ground for his new security campaign. Palestinian Prime Minister Salaam Fayad said that if the security forces can impose control in chaotic Nablus, they would gradually try to do the same in other West Bank cities. Israel has raised doubts about Abbas's ability to control the West Bank and implement any peace deal, after his security forces were defeated in a few days of fighting with the Islamic militant group Hamas in Gaza in June. The security clampdown is part of Abbas's attempt to show that it is meeting his obligations under the first phase of the "road map" peace plan. Under the plan, Israel has to freeze expansion of West Bank settlements, dismantle dozens of wildcat settlement outposts, remove major West Bank roadblocks and pull troops back to where they were before the October 2000 outbreak of violence. Israeli government official David Baker welcomed the Nablus operation, but wouldn't say whether it should be interpreted as a step to Palestinian implementation of road map provisions. "Israel views any vigorous and robust activity by the Palestinians to maintain order and combat terror to be a positive development, which we feel is overdue and most welcome," Baker said.