NABLUS  - Palestinian security forces arrested more than 50 Hamas members in the West Bank Monday in an apparent tit-for-tat action after the Islamist movement rounded up hundreds of its rivals in the Gaza Strip. Security forces loyal to Palestinian president Mahmud Abbas carried out the arrests in and around the northern West Bank town of Nablus against "those suspected of inciting civil strife," a Palestinian security official told AFP. All but one of the detainees are Hamas members, and those arrested include several prominent local leaders and university professors. The wave of arrests came amid a widening Hamas crackdown in the Gaza Strip in which more than 300 members of Abbas's Fatah party, which was largely driven from the territory when Hamas took over, have been detained in the past three days. A senior security official in the West Bank political capital of Ramallah said 150 people, most of them Hamas members, had been arrested in the past week but denied that the arrests had any connection to events in Gaza. "The arrests are not political but are against outlaws," the official said. "They were given the opportunity to live their lives and conduct their political activities according to the law but they did not do that." In Gaza, meanwhile, Hamas continued to raid homes, offices, sporting clubs and charities, most of them linked to Fatah, and arrested dozens more people, a senior Fatah official told AFP on condition of anonymity. Hamas also halted distribution in Gaza of the three main Palestinian newspapers - Al-Ayyam, Al-Quds and Al-Hayat Al-Jedida, according to Sami al-Qishawi, a senior manager at Al-Ayyam. "They did not give any reason," Qishawi told AFP, adding that Hamas-run security forces had blocked shipments of the papers at the Erez crossing between Israel and Gaza. Al-Hayat Al-Jedida is considered close to Abbas's West Bank authority, while the other two are regarded as politically neutral. The two main Palestinian factions have been bitterly divided since Hamas seized power in Gaza in June 2007 after driving Abbas's security forces out of the impoverished territory in a week of bloody street battles.