Defiant Hamas officials said on Thursday that the arrest by the IDF of 10 senior Hamas representatives in the West Bank would not make them change their demands for the release of St.-Sgt. Gilad Schalit, who is being held captive in the Gaza Strip. The IDF said the pre-dawn arrests came because of the suspects' recent activity in attempting to bolster the group's presence in the area. "These men have been the leaders of the ongoing effort to restore the administrative branch of the Hamas terror organization in the region, while attempting to increase the power and influence of Hamas," the IDF Spokesman said in a statement. The Hamas officials also directed their anger at the Palestinian Authority security forces in the West Bank and accused them of collaborating with Israel. They pointed out that in recent days PA forces had arrested more than 15 Hamas supporters. Hamas legislator Yahya Musa condemned the PA security forces as a "fifth column" that is operating on instructions from the IDF, and urged Palestinians to use their shoes to drive these forces and the PA leadership out of the West Bank. Yahya and other Hamas spokesmen warned that the latest Israeli measures, including plans to deny Hamas prisoners most of their privileges, would have a negative impact on Schalit. "The arrest of senior Hamas officials won't force Hamas to make concessions regarding the case of Schalit," said Hamas legislator Salah Bardaweel. "This is a clear attempt to blackmail Hamas and force it to sign a prisoner exchange agreement without gaining anything in return." Bardaweel added that the arrests "reflected the state of confusion" in Israel following the collapse of the negotiations over the release of Schalit in Cairo earlier this week. "The occupation has failed to bring Hamas to its knees through force and is now resorting to repressive measures," he charged. "All these measures against Hamas are immoral." Another Hamas legislator and spokesman, Mushir al-Masri, called on the Egyptians to "assume their responsibilities and declare which party was responsible for the failure of the talks." He strongly condemned the arrest of the Hamas officials as a "cheap attempt to blackmail Hamas." Masri stressed that the arrests would not deter Hamas and would even make the movement more determined to achieve its goals. "In the past, they arrested Hamas legislators and officials, to no avail," he continued. "They are tampering with the fate of the soldier [Schalit] through such adventures." The Hamas officials were arrested in Ramallah, Nablus, Hebron and Bethlehem. They included Nasser Eddin al-Shaer, the former deputy prime minister in the Hamas government; Adnan Asfour, a Hamas political leader; and legislators Ayman Daraghmeh, Khaled Tafesh, Azzam Salhab, Abdel Jaber Fukaha and Nizar Ramadan. They had all been arrested shortly after the kidnapping of Schalit, but were released over the past few months. Palestinian sources said another 12 Hamas supporters were arrested by the IDF in the past 24 hours, among them three men who had just been released from a PA prison in Hebron. The three were Yusef Awawdeh, Mohammed Takhman and Mohammed al-Atrash. According to the sources, the three were released after spending six months in PA prisons without trial or the possibility to see a lawyer.