Islamist rebels in Mali have seized control of a small town from government forces, despite the military intervention by France.
Reports say the counter-attack on Diabali was led by a leader of one of the main jihadist groups, al-Qaeda in the Islamic Maghreb.
One security source said the rebels came from the Mauritanian border to avoid being bombarded by French planes. They reportedly crossed a river in small groups to re-take the town 400 kilometres north of the capital Bamako.
France has said it does not want to act alone in Mali. The French Defence Minister Jean-Yves Le Drian said overall the intervention was going well, and in eastern Mali the rebels had been forced back.
“There remains one difficult point in the west, where we are dealing with heavily armed groups and where operations are taking place at the moment alongside Malian forces who fought bravely last Friday in the east,” he said.
France has called for a meeting of the UN Security Council. It says its intervention on Friday in the face of a rebel advance stopped the Islamists from seizing the capital.
President Hollande says the aim is simply to support a West African military mission to retake northern Mali.
Islamist leaders have threatened to attack France in retaliation.
Britain is sending a cargo plane carrying military equipment and medical facilities for the French forces.
Meanwhile Algeria has said it is closing its borders with Mali.