Ethiopia ? Investigators were working “around the clock” to find five Europeans linked to the British embassy, but no one has claimed responsibility for their disappearance in a remote border region of Ethiopia, the British Foreign Office said Tuesday.

The five Europeans were in a tour group, which included 13 Ethiopian drivers and translators, that disappeared Thursday while traveling in Ethiopia’s Afar region, a barren expanse of salt mines and volcanoes 500 miles northeast of the capital, Addis Ababa.

The five are employees of the British Embassy in Addis Ababa, or their relatives. A spokesman for the British Foreign Office and the French foreign minister said one of the five is French.

“We are in contact with the British authorities in London and Addis Ababa, and I am personally following this affair,” French Foreign Minister Philippe Douste-Blazy said.

There was no word on who was behind the kidnapping.