Sudanese officials could not confirm the Libyan reports that the group has re-crossed the desert border back into Sudan.
"We are checking, we are working hard on that, but we have no information at present," Ali Yousuf, head of protocol at the Sudanese foreign ministry, said.
However, he said the hostages are all reported to be well.
"They are all ok, that's the latest news," he added.
The safari group was attacked almost a week ago near Gilf al-Kabir region, a sandstone plateau close to the border with Libya and Sudan.
The abducted foreign tourists include Germans, Italians and Romanians.
Germany's foreign ministry said on Thursday that it had formed a "crisis team". Egyptian officials said Germany was negotiating a ransom with the kidnappers.
Egypt's Middle East News Agency said the ransom demand was as high as $15m, while Zoheir Garana, the Egyptian tourism minister, has said the tour company that organised the safari was negotiating in the range of $6m.
"Military forces are in the area, but we are not going to make any move that puts the lives of those being held in any risk," Yousuf said.
"Germany is in contact with the kidnappers, and Sudan is remaining in close contact with the Egyptian, Italian, German and Romanian authorities."
Egypt has said Germany is negotiating through the German wife of the Egyptian tour operator who is among the missing, saying she would be given the ransom to hand over.