Undated file picture showing Egypt's southwestern desert, where a group of tourists and Egyptians were kidnapped during an adventure safari

Sudanese officials say kidnappers holding 19 people hostage have moved with their captives from Sudan into Libya.

A Sudanese foreign ministry official, Ali Yousuf, said Thursday the group has moved about 15 kilometers across the Libyan border.

Sudanese officials say the 11 European tourists and eight Egyptians being held hostage are alive and healthy.

The group was abducted last Friday during a desert expedition in southwestern Egypt and taken across the border to Sudan.

Sudanese officials had said they would not mount a military rescue operation because it might endanger the hostages' lives.

Officials say the German government is in contact with the kidnappers, who are said to be asking for at least $9 million in ransom.

Germany is reported to be leading the negotiations through the German wife of a tour operator who is among the missing.

The identity of the kidnappers remains unclear.  

Kidnappings of foreigners are rare in Egypt, although militants have killed many people in bombings and shootings at tourist sites.

Some information for this report was provided by AFP, AP and Reuters.