Islamist rebels in Somalia say a second French soldier has died of his wounds after a failed rescue attempt.
A spokesman for al-Shabab told the Reuters news agency that the commando had died of gunshot wounds and that both bodies would be shown later.
France’s defence minister said he believed the soldier was indeed dead.
The French military sent a force into southern Somalia late on Friday to try to free Denis Allex, an intelligence agent held hostage since 2009.
The militants say he is still alive, with his fate yet to be decided.
The raid came hours after French troops had intervened in the west African state of Mali.
On Monday, al-Shabab spokesman Sheikh Abdiasis Abu Musab told Reuters: “The second commando died from his bullet wounds. We shall display the bodies of the two Frenchmen.”
French Defence Minister Jean-Yves Le Drian later said it appeared that the second French soldier had been killed.
“All indications unfortunately lead us to believe that al-Shabab are preparing to organise a disgraceful and macabre display,” he added.
On Saturday, French President Francois Hollande said Mr Allex – a codename – had in all probability been killed by his captors during the rescue operation. Al-Shabab has offered no proof that Mr Allex is alive.
A battle erupted with al-Shabab militants after commandos swooped on the town of Bulo Marer on Friday night and Saturday morning. France says 17 militants were killed in the fighting.
On Sunday, Mr Le Drian defended the raid in an interview on French radio.
“It’s good to talk, to look for a deal, but we cannot bow to unreasonable conditions, as was the case with the Shabab.
“The Shabab were asking for the release of I don’t know how many jihadist prisoners around the world. It was impossible and completely unrealistic,” he added.
A senior al-Shabab commander, Sheikh Mohamed Ibrahim, told the AFP news agency that it had been warned about the impending raid, but gave no more details.
Somali witnesses said a number of civilians had also been killed in the operation, which involved some 50 troops and at least five helicopters.
On Sunday, President Barack Obama acknowledged US forces had provided some technical support for the French operation.
He wrote in a letter to Congress: “United States combat aircraft briefly entered Somali airspace to support the rescue operation, if needed.”
Mr Allex appeared in a video in June 2010, appealing to France to drop its support for the Somali government.
He last appeared in another video in October, looking gaunt and calling on President Hollande to work for his release.
Somalia has not had an effective central government for more than two decades.
France has a large military base in neighbouring Djibouti, including army, marine and air force units.