Palestinian militants of a group linked to Fatah faction abducted a senior official of rival Hamas faction in the West Bank on Saturday (January 6). Twelve gunmen of the al-Aqsa Martyrs Brigades, a militant group linked to Palestinian President Mahmoud Abbas's Fatah movement, kidnapped the deputy mayor of the town of Nablus in the West Bank, who is a senior official of Hamas. In a video that the al-Aqsa Martyrs Brigades group made available to Reuters hours after the kidnapping, masked militants can be seen holding the Hamas official while they are armed. "We will not let this pass without paying for it for the crimes of these criminals," says one of the militants. "The leaders who committed these crimes against our people in Gaza will pay a heavy price for crimes in the West Bank and we will not differentiate between leaders. The blood of Fatah members is expensive and honourable. We will not be the attackers but we will protect our people wherever they are. It is a revolution until victory," he adds. Mahdi al-Hambali, 40, was in his car when gunmen opened fire at him, smashed the car and took him away, witnesses said. The Nablus kidnapping followed a similar act in the West Bank city of Ramallah, where gunmen stormed an office of the Interior Ministry which is controlled by Hamas, shot a ministry's worker, a Hamas member, in the leg, took him away and left him wounded outside the city. Some Palestinians fear civil war in the wake of Abbas's call last month for fresh parliamentary and presidential elections to break a political deadlock with Hamas after the two sides failed to form a unity government. Hamas trounced Fatah in elections in January 2006 but the two sides have been locked in bitter conflict ever since. Abbas arrived at the West Bank town of Bethlehem on Saturday (January 6) to attend the Eastern Greek Orthodox celebration of Christmas eve and midnight mass. Abbas's visit to Bethlehem comes after a statement was issued form the President's office declaring Hamas executive force as illegitimate force. This statement comes two days after Abbas and Hanniyeh met to calm the tension between Fatah and Hamas forces within the West bank and Gaza. Abbas's spokesman said the Hamas force would remain illegal until it complied with a previous decision by Abbas to integrate into the established security apparatus. "With regards to the executive force and since we established it, it wasn't an independent force, but we said it must be part of the security forces. To establish any force, it needs a decree and this decree has not been issued until this moment. And who ever says that its an independent force, he is defying the law and the constitution." Abbas told reporters. Earlier on Saturday the Interior ministry spokesperson warned of any harm to its forces. Abbas's decision came two days after members of the Hamas force attacked a house of a senior security official from the Preventive Security force, which is loyal to Abbas's Fatah faction. The gunmen killed the Colonel and six of his men. Hamas says the Executive Force has nearly 5,500 members and will be expanded. Hamas receives funding from Iran and other Islamist allies. Speaking hours after the announcement, a spokesman for the Hamas force said its numbers would double from nearly 6,000. "The president's office should have worked on calming the situation instead of inciting and making the situation more complicated on the Palestinian arena," spokesman Islam Shahwan said as forces of Hamas were training in the southern Gaza town of Khan Younis. Abbas's decision is likely to further fuel tension between Hamas and the moderate president's once-dominant Fatah faction.