A Canadian woman and an Italian man who were abducted 15 months ago in Burkina Faso have been released in the neighboring country of Mali, a United Nations official confirmed Saturday.

Edith Blais of Quebec and her Italian traveling companion, Luca Tacchetto, went missing in December 2018 in an area of Burkina Faso that is known to be a stronghold of the Islamic State’s local franchise, the same group responsible for killing four American soldiers in Niger the previous year.

An American official who had been briefed on their release said they were let go late Friday in the city of Kidal in Mali’s far north. It was not clear which group had been holding them or under what conditions they were released.

Their release was confirmed on Saturday by a spokesman for the United Nations’ peacekeeping mission in Mali. The spokesman, Olivier Salgado, said the two spent the night at the mission’s base in Kidal before flying to the capital, Bamako, on Saturday.