Unidentified gunmen are negotiating with Palestinian officials in the Gaza Strip for the release of a 25-year-old British woman and her parents whom they kidnapped yesterday.The woman is believed to be Kate Burton, who works for local human rights group Al Mezan. The abduction of foreigners is not unusual in the area and hostages are usually released unharmed within hours. Generally, militant groups use the hostages to press the Palestinian authorities for money, jobs or the release of prisoners. The British woman was showing her parents around the town of Rafah when they were bundled into a car and driven away. Palestinian infighting has worsened before the legislative elections next month. Employees at the Central Election Committee office in Gaza City had to dive for cover yesterday as Palestinian gunmen briefly exchanged fire with police.There were no reports of casualties. The gunmen, from the mainstream Fatah faction of President Mahmoud Abbas, were unhappy with their representation on a new list of candidates. Facing a strong challenge from the Islamist movemement Hamas, rival wings of Fatah have agreed to submit a joint list. It takes in veteran politicians and younger members loyal to jailed West Bank leader Marwan Barghouti.