PARIS (AP) — Two French soldiers have been killed in a military operation in the West African nation of Burkina Faso that freed four people from the U.S., France and South Korea who were kidnapped in neighboring Benin.

In a statement Friday, French President Emmanuel Macron expressed condolences for the two soldiers killed in the overnight operation. He thanked authorities in Burkina Faso and Benin for their cooperation in the mission, and promised them support in fighting terrorism in the Sahel region.

Two of the hostages were French tourists, one was an American and the other a South Korean, Macron's office said. It did not identify the hostage-takers.

The French tourists failed to return from a visit last week to the Pendjari National Park wildlife reserve. Their African guide was later found dead.

Macron's office did not immediately release information on the American or the South Korean.

Islamic extremists have become increasingly active in Burkina Faso, raising worries the militants could be infiltrating northern Benin and neighboring Togo as well.

France has 4,500 troops in a military force in the Sahel aimed at helping local governments fight Islamic extremists.

Pendjari National Park is part of a vast wildlife area that stretches across the countries of Benin, Burkina Faso and Niger. The entire area is home to most of the world's remaining West African lion population.