French hostages killed during Niger rescue bid

France warned its citizens to avoid the Sahel region of North-west Africa yesterday after two Frenchmen were murdered by kidnappers, probably linked to al-Qa'ida, during a running battle with Nigerian and French forces.

The two men, both 25, were childhood friends from the Lille area. Antoine de Léocour was an aid worker in Niger who was due to marry a woman from neighbouring Nigeria next week. His friend, Vincent Delory, had flown out to be his best man.

The pair were abducted from a restaurant in Niger's capital, Niamey, on Friday. Their kidnappers were tracked by a French surveillance aircraft as they crossed the Nigerian border and doubled-back through Niger towards their presumed bases in southern Mali. Nigerian and French troops twice attacked the group. After the second firefight, the bodies of the men were found in the desert nearby. The French military said they appeared to have been "executed".

Nigerian military officials said that all the abductors had later been killed by Nigerian and French soldiers.

The killings, the latest of a series of attacks on French citizens in the Sahel, produced a wave of anger and revulsion in France. Six other French people have been abducted in Niger in the past nine months.

The President, Nicolas Sarkozy, condemned what he described as a "barbarous and cowardly act". The Environment minister, Nathalie Kosciusko-Morizet, called the killings "an act of war". The foreign ministry said that "no area can be considered safe [for French citizens] any longer in the entire Sahel region", covering Senegal, Mauritania, Burkina Faso, Mali, Niger, Chad and Northern Nigeria.

Because of France's colonial links with the region, there are scores of French aid and commercial workers in the Sahel. Paris fears that its citizens have become the target-of-choice for extreme islamist or bandit groups linked to an organisation which calls itself al-Qa'ida in the Islamic Maghreb, or AQIM.

AQIM, which operates across the uncontrolled borders in the Sahara desert, is already holding five French citizens and two other westerners. Axel Poniatowski, the president of the National Assembly foreign affairs committee, said French nationals had become the "hostage of choice" partly because of legislation banning the burka.

Another French hostage, Michel Germaneau, 78, was killed by AQIM in July after a failed French rescue mission in Mali following his abduction in Niger. The Defence minister, Alain Juppé, will fly to Niamey today.

Nigerian and French officials rejected suggestions that the two men might have died in crossfire or in friendly fire. They said the hostages' bodies were found away from the immediate area of a final battle. "The kidnappers were killed in their car. They were the only people in the car at the time of the clash so the execution happened beforehand," a Nigerian official said.

Rakia Hassan Kouka, the young Nigerian woman who was due to marry Mr Leocour this week, gave a brief, tearful interview to French radio yesterday. "It's impossible to say what is in my heart," she said. "I can only pray to God that he rests in peace."