DAKAR, Senegal — Islamists advanced into territory held by the Mali government on Thursday, overrunning a long-held defensive position in the center of the country and dealing a significant blow to the Malian Army in its attempt to contain the militants who have seized the nation’s north, according to a Malian Army officer.
Over the last two days, clashes have erupted between the army and militants around Konna, a sleepy mud-brick village that for months had marked the outer limit of the Malian Army’s control after it lost half of the country to Islamists and their allies last April.
On Thursday, though, the town appeared to have fallen to the Islamists, forcing Mali’s army to retreat and inflicting losses on it. The Malian officer, reached by phone in Bamako, the capital, was categorical, confirming the loss of Konna and calling the situation “critical” for the Malian Army.
“It’s a very serious situation, very dangerous,” said the officer, who was not authorized to speak publicly.
The Islamists now threaten a major airfield some 25 miles away at the town of Sévaré, which is also the home of a significant army base. And 10 miles from Sévaré is the historic river city of Mopti, the last major town controlled by the Malian government, with a population of more than 100,000.
“There were hard fights, but we lost,” the officer said.
“The Malian Army has retreated to Sévaré,” he said. “We need the help of everybody to save Sévaré.”
A spokesman for the Islamists, Sanda Ould Boumana, said from rebel-held Timbuktu: “We have taken the town of Konna. We control Konna, and the Malian Army has fled. We have pushed them back.”
The army’s official spokesman, Lt. Col. Diarran Kone, refused to confirm or deny the loss of the village. Gen. Carter F. Ham, the commander of the Pentagon’s Africa Command, who was traveling in neighboring Niger on Thursday, said that he had seen the reports from Mali but could not yet independently verify them.
“If true, this is a significant change in the situation,” General Ham said.
This week’s clashes were the first time that the two sides had fought since Islamists and their Tuareg rebel allies conquered the north of Mali last spring, splitting the country in two and leaving the Malian Army in disarray.
For months, the United Nations and Mali’s neighbors have been debating and planning a military campaign to retake the north by force, if necessary, an international push that is supposed to be led by Malian forces. Analysts had previously said that the outcome of this week’s fighting at Konna would be a significant indicator of the army’s fitness to undertake the reconquest of the north.
Its loss now raises serious questions about the plan, tentatively approved by the United Nations Security Council last month. A retooled Malian Army was to be the plan’s centerpiece, aided by troops from around the region.
The rebel advance prompted the Security Council to meet Thursday night in an emergency session on the deteriorating situation. Afterward it issued a statement expressing “grave concern” as well as determination to enforce previous resolutions on ending the crisis, including the dispatching of an African-led force to help the government reclaim lost territory.
France’s ambassador to the United Nations, Gérard Araud, who had called for the meeting, confirmed that Mali’s interim president, Dioncounda Traore, had sent a letter to President François Hollande of France and the president of the Security Council seeking help in countering the Islamists’ latest advance.
Mr. Hollande said on Friday he was ready to respond to Mali’s appeal for assistance, The Associated Press reported. He said France would seek a United Nations resolution for action but that it was “ready to stop the terrorists’ advance if it continues.”
The loss of Konna could add urgency to Western preparations — France and to some extent the United States have pledged assistance — aimed at extinguishing the quasi-state of militants. Many of them belong to, or are affiliated with, Al Qaeda in the Islamic Maghreb, which controls a vast portion of territory in West Africa.