French Prime Minister Jean-Marc Ayrault on Monday denounced the publication by Somalia's Al-Qaeda-linked Shebab of photographs of an alleged French commando chief killed in a botched hostage rescue operation.

"This is a particularly odious display," Ayrault told journalists in the northwestern city of Caen, after Shebab posted the photographs on its Twitter account.

"This particularly dangerous operation failed but the government claims it fully because there can be no complacency in the face of terrorism," Ayrault said.

France's military operation Saturday to free a French spy held hostage by the Shebab since July 2009 was a failure, with two French soldiers reported killed in the raid and the fate of the hostage unclear.

Shebab said Monday its members had decided the "fate" of the French intelligence agent, Denis Allex, and would make an announcement in the coming hours.