Militants threatening to kill three foreign hostages in Afghanistan on Monday allowed four days for negotiations on their demand that the United Nations withdraw from the country. One day after a video was aired, showing the three U.N. workers pleading for freedom, the Taliban splinter group claiming to hold them also said the trio had been split up to thwart any rescue. "That's our strategy," Ishaq Manzoor, a spokesman for the group, told The Associated Press in a satellite telephone call. "If the government and coalition forces find one of them, we will kill the other two." Afghan security officials say they have had no contact with the kidnappers, who plucked the three _ two women from Kosovo and Northern Ireland, and a Filipino man _ from a U.N. vehicle at gunpoint in the capital on Thursday. But Manzoor insisted that a businessman was carrying messages between the militants and the Afghan government and the United Nations.