Malian government forces yesterday launched an offensive against Islamists controlling the north of the country with backing from the French and other foreign military, military and political sources said.
The attack was aimed at stemming advances made by al-Qaeda-linked radicals who this week triggered international alarm with a push south towards the capital, Bamako, a military officer said.
"Our offensive has started," the officer said. "The objective is to retake total control of the town of Konna and to proceed from there."
He added that "military planes from friendly countries" were being used in the offensive, while a Malian government official said the operation had the support of French and European armed forces.
With the situation on the ground developing rapidly, France advised all its expatriates not involved in essential services to leave Mali immediately.
French Defence Minister Jean-Yves Le Drian was in contact with US Defence Secretary Leon Panetta and was due to talk to his British and German counterparts late yesterday.
The offensive came a day after Mali's government appealed to France, the former colonial power, and the United Nations for help in pushing back the Islamists.
As well as capturing Konna, the rebel forces have moved about 1,200 Islamist fighters to within 20 kilometres of Mopti, a strategically important town on the frontier between rebel-held and government-held territories.
French President Francois Hollande responded to Mali's appeal yesterday by saying Paris was ready to help, under the auspices of the UN.
The UN Security Council has already given its blessing for a 3,000-strong African force to be sent to Mali but it will not be ready to deploy before September at the earliest.
That has put pressure on France to act quickly and Hollande acknowledged that the situation had become critical.