Sudanese troops are keeping watch over a band of kidnappers holed up in the desert after snatching a 19-member tour group in Egypt, but are not closing in on them, fearing any move could endanger the hostages, Sudan's Foreign Ministry said Wednesday. Germany, five of whose citizens are among the captives, has been negotiating with the kidnappers since they were snatched on Friday while on a Sahara desert safari to a remote plateau in the southwestern corner of Egypt, according to Egyptian officials. Negotiations have been taking place through two phone calls a day between the tour company's owner, who was among those kidnapped, and his German wife, who lives in Egypt, an Egyptian security official said, speaking on condition of anonymity because he was not authorized to discuss details of the talks. Much about the abduction remains mysterious, particularly the identity of the kidnappers. They are believed to be desert tribesmen, and Egypt's state news agency MENA has said they are demanding up to $15 million in ransom. Sudan said Tuesday it believes they are Egyptians, but MENA on Wednesday quoted an unidentified Egyptian security official saying they were “most likely not Egyptians.” So far, it is not known if German officials have spoken directly to the kidnappers or if all communications have been passed through the tour operator and his wife. Italian media reported that the wife was being hosted at the German Embassy in Cairo. In one of the initial calls, the tour operator reportedly described the kidnappers as “African” in appearance. The group of five Germans, five Italians, a Romanian, and eight Egyptian guides and drivers was abducted while visiting the Gilf Al-Kebir, an isolated plateau some 885 kilometers southwest of Cairo in Egypt's Western Desert. The site is little visited, with only a few hundred adventure tourists a year making the grueling desert journey, drawn by the location's dramatic desert scenery and the rich troves of prehistoric art in the plateau's numerous caves. Sudan says the kidnappers have been located in the desert of northwestern Sudan, about 15 miles (25 kilometers) from the Egyptian border. “We are now in remote surveillance (of the kidnappers) but we are not planning to storm the place or threaten the lives of hostages,” Sudanese Foreign Ministry spokesman Ali Youssef told The Associated Press. “No military action is considered at all.” Germany has been silent on any negotiations, refusing to even confirm that it is conducting them. “I ask you to understand that it won't help anyone if we approach the press with any of the details,” Foreign Ministry spokesman Andreas Peschke said Wednesday. “I think we have a good reason to carry out our public relations in the way that we do.” Egyptian security officials have been questioning tribesmen in the Western Desert, where the plateau is located, trying to get clues to the kidnappers' identity and are searching areas near the Sudanese border for anyone else who may have been involved, an Egyptian security official said. He spoke on condition of anonymity because he was not authorized to talk to the press. __