Two French tourists who were held hostage in Burkina Faso have thanked the French soldiers who "lost their lives to free us from this hell".
Two French special forces soldiers, Cédric de Pierrepont and Alain Bertoncello, died during the raid, which rescued four hostages and killed four kidnappers.
"All our thoughts go out to the families of the soldiers and to the soldiers," said one of the French hostages, Laurent Lassimouillas.
Two hostages, from the United States and South Korea, have not yet been named.
Mr Lassimouillas was kidnapped on 1 May along with Patrick Picque. The two music teachers were on safari in the remote Pendjari National Park in northern Benin.
The pair, along with the South Korean, have now returned to France, arriving this week at Villacoublay airport outside Paris to be greeted by President Emmanuel Macron.
Mr Macron has announced a national tribute will be held next week in Paris in honour of the soldiers.
Mr Lassimouillas said: "We would like to thank the French authorities and those of Burkina Faso for participating in our liberation, so that we are now very far from all this hell we have been through."
He also paid tribute to the pair's Beninese driver and guide, who was killed by the kidnappers.
French Foreign Minister Jean-Yves Le Drian urged people to take note of official travel warnings.
"The zone where our two citizens were has for some time now been considered a red zone, which means it's a zone where you shouldn't go, where you're taking significant risks if you do go," Mr Le Drian told Europe 1 radio.
What do we know about the raid?
The raid took place at night in the north of Burkina Faso as the kidnappers stopped on their journey towards Mali, the head of the French military, General François Lecointre, told reporters.
Commanders decided to act because the kidnappers were close to the Malian border and were believed to be planning to hand the hostages over to the Mali-based militant group Katiba Macina.
"Once the hostages were in their hands it would have been impossible to rescue them," General Lecointre said. He said that a first operation, conducted with United States support, had allowed the French to track the kidnappers.
During the raid itself, special forces covered 200m of open ground and got to within 10m of the shelter where the hostages were being held before being spotted by a guard.
The two French soldiers who died were killed at close quarters as they entered one of the kidnappers' four shelters, the general said.
Troops did not expect to find the US and South Korean hostages, because there had been no information that the kidnappers were holding anyone else, French Armed Forces Minister Florence Parly said.
Ms Parly said the kidnappers' identity was not yet known, but there were two main militant groups operating near where the French tourists were taken, one linked to al-Qaeda and the other to the Islamic State group.
Ms Parly thanked the militaries of Benin and Burkina Faso for their help in the operation.
How were the hostages taken?
Mr Picque, Mr Lassimouillas and their guide disappeared from the Pendjari National Park. The disfigured body of their guide was found shortly after they disappeared, along with their abandoned vehicle.
The park sits on the border with Burkina Faso, where Islamist militants have been increasingly active in recent months.
The other two liberated hostages had apparently already been in the kidnappers' hands for 28 days, General Lecointre said.
South Korea's Yonhap news agency quoted the country's ministry of foreign affairs as saying the rescued South Korean national was in her 40s and has not been named.
"We've made contact with her family here and notified them of her health conditions," the ministry was quoted as saying.
The US expressed its gratitude to France for the American woman's release, AFP quoted an official as saying. France said it was likely that she would be "repatriated independently" from the other three.
What reaction has there been?
A statement said Mr Macron "bows with emotion and solemnity before the sacrifice of our two soldiers who gave their lives to save those of our citizens".
Ms Parly said "terrorists who attack France and French citizens should know that we will spare no effort to track them down and fight them".
France has 4500 troops based in the Sahel region on the southern edge of the Sahara Desert as part of its Operation Barkhane, an ongoing coalition effort in Africa's Sahel region to fight jihadist insurgents.
A total of 24 French soldiers have died in the region since 2013, when France intervened to drive back jihadist groups who had taken control of northern Mali.