Radical Islamists held on to a city in central Mali Friday after sending the Malian military reeling in retreat. With the militants showing the capability to press even further into government-held territory, international aid organizations began evacuating staff from the narrow central belt of the country.

Residents who live near an airport about 30 miles (50 kilometers) from the captured town on Konna reported hearing planes arrive throughout the night. Who, or what, the planes were bringing could not be immediately determined.

The United Nations Security Council condemned the capture of Konna and called on U.N. member states to provide assistance to Mali "in order to reduce the threat posed by terrorist organizations and associated groups."

A regional military intervention to take back northern Mali from the Islamists was not likely before September, though the advance by the Islamists creates pressure for earlier military action.

On Friday, French President Francois Hollande said the former colonial power is ready to help to the stop the Islamist extremists. He did not specify what assistance it is prepared to offer.

"France, like its African partners and the entire international community, cannot accept that," he said in a speech to France's diplomatic corps, referring to the Islamists' advances in the desert nation in northwest Africa.

A top French diplomat, who spoke on condition of anonymity because he was not authorized to speak publicly on the matter, said that France is now able to deploy military assets — notably air power — over Mali "very quickly."

He insisted that Hollande's speech is "not just words. ... When you say that you are ready to intervene, you have to be."

However, he declined to provide details about how such military action might take shape. France's position has been complicated because kidnappers in northern Mali hold seven French hostages.

For months, Hollande has said France would not send ground forces into Mali, and France is sticking to those plans, the official said. But Hollande's speech suggested that French air power could be used, the official said.

The fighting Wednesday and Thursday over the town of Konna represents the first clashes between Malian government forces and the Islamists in nearly a year, since the time the militants seized the northern cities of Gao, Kidal and Timbuktu.

The Islamists seized the town of Douentza four months ago after brief standoff with a local militia, but pushed no further until clashes broke out late Wednesday in Konna, a city of 50,000 people, where fearful residents cowered inside their homes. Konna is just 45 miles (70 kilometers) north of the government-held town of Mopti, a strategic port city along the Niger River.

"We have chased the army out of the town of Konna, which we have occupied since 11 a.m.," declared Sanda Abou Mohamed, a spokesman for the Ansar Dine militant group, speaking by telephone from Timbuktu.

A soldier, who spoke on condition of anonymity because he was not authorized to speak to journalists, acknowledged that the army had retreated from Konna. He said several soldiers were killed and wounded, though he did not have precise casualty figures. "We didn't have time to count them," he said.

While Konna is not a large town, it has strategic value as "the last big thing ... on the road to Mopti," said J. Peter Pham, director of the Africa program at the Washington-based Atlantic Council.

"I think the real target here is to seize the airstrip in Mopti, either to hold it or blow enough holes in it to render it useless," Pham said. "If you can seize the airstrip at Mopti, the Malian military's and African militaries' ability to fly reconnaissance in the north is essentially clipped."

Al-Qaida's affiliate in Africa has been a shadowy presence for years in the forests and deserts of Mali, a country hobbled by poverty and a relentless cycle of hunger. Most Malians adhere to a moderate form of Islam, where women do not wear burqas and few practice the strict form of the religion.

In recent months, however, the terror syndicate and its allies have taken advantage of political instability to push into Mali's northern towns, taking over an enormous territory they are using to stock weapons, train forces and prepare for jihad.

The Islamists insist they want to impose Shariah only in northern Mali, though there long have been fears they could push further south. Bamako, the capital, is 435 miles (700 kilometers) from Islamist-held territory.

The retreat by the Malian military raises questions about its ability to participate in a regional intervention.

Late last year, the 15 nations in West Africa, including Mali, agreed on a proposal for the military to take back the north, and sought backing from the United Nations.

The U.N. Security Council has authorized the intervention but imposed certain conditions. Those include training of Mali's military, which has been accused of serious human rights abuses since a military coup last year sent the nation into disarray.