French forces have freed two Frenchmen, an American and a South Korean citizen who were being held hostages in Africa's Sahel region, France said on Friday. Two French soldiers were killed in a military operation conducted overnight, according to a statement released by French President Emmanuel Macron. The statement did not indicate who was holding the tourists. Defence Minister Florence Parly thanked authorities in Benin and Burkina Faso for their help with the "complex operation", as well as the United States for its "precious support". The statements did not identify the American and South Korean hostages but they were both said to be women. The French tourists, identified as Patrick Picque and Laurent Lassimouillas, disappeared in the remote Pendjari National Park in Benin on May 1 and their local guide was later found dead. The vehicle they were travelling in was found just across the border in Burkina Faso. The two men, music teachers from the Paris region, are expected to travel back to France on Sunday. Although Benin is considered an island of stability in West Africa, a troubled region where many extremist groups operate, Pendjari lies on the porous and remote border with Burkina Faso, which has been hard-hit by militant violence. In his statement on Friday, Mr Macron promised support to Burkina Faso and Benin in fighting terrorism in the Sahel region. Burkina Faso lies in the heart of the Sahel, a vast semi-arid region bordering the Sahara. The region turned into a hotbed of violent extremism and lawlessness after chaos engulfed Libya in 2011. At first concentrated in the north of the country, the attacks have spread to other regions including the east, which borders Togo and Benin. Militant groups operating in the region include Ansarul Islam group, the Group to Support Islam and Muslims (GSIM) and ISIS in the Greater Sahara. Burkina Faso, Chad, Mali, Mauritania and Niger formed the G5 Sahel group in 2014 to co-operate on development and security. The French military has been involved in anti-militant operations in all five nations in recent years, beginning with its intervention in Mali in 2013 after Al Qaeda-linked groups seized the north of the country.