BAMAKO, Mali — French ground troops battled armed Islamist occupiers of a desert village in central Mali on Wednesday, a Malian army colonel said, in the first direct combat between them since France launched its military operation here last week to help wrest this nation back from an Islamic jihadist expansion.
The Malian colonel, who also said his army's ground troops had joined the French forces, reported that they had ringed the village of Diabaly, which Islamist fighters had seized the day before, and were engaged in fighting to extricate them. "It's a very specialized kind of war," said the colonel, who spoke on condition of anonymity. "The town is surrounded."
The ground fighting expanded the confrontation between the Islamists and the French forces, which had been largely limited to aerial assaults since President François Hollande of France ordered an intervention in Mali last Friday to thwart a push to the south by Islamist rebels controlling the north of the country.
The Diabaly battle followed a northward push by a French phalanx of armored vehicles from the capital of Bamako to confront the Islamist expansion. It came as news reports from the region said Islamist militants from northern Mali affiliated with Al Qaeda in the Islamic Maghreb had seized a foreign-run gas field near the Algeria-Libya border, hundreds of miles away, and had seized dozens of foreign hostages in retaliation for the French intervention in Mali and for Algeria's cooperation in that effort.
The developments came soon after Defense Minister Jean-Yves Le Drian of France forecast a protracted campaign to turn back a southward thrust by the rebels from their redoubts in the northern Malian desert.
"We're in a better position than last week, but the combat continues and it will be long, I imagine," he said Wednesday on RTL radio. "Today the ground forces are in the process of deploying," he said. "Now the French forces are reaching the north."
Adm. Edouard Guillaud, the French chief of staff, told Europe 1 television that ground operations began overnight.
He accused jihadists of using civilians as human shields and said, "We refuse to put the population at risk. If there is doubt, we will not fire."
In Paris, Mr. Hollande said Wednesday that he took the decision to intervene last Friday because it was necessary. If he had not done so, it would have been too late. "Mali would have been entirely conquered and the terrorists would today be in a position of strength."
On Tuesday, witnesses in Mali reported, the insurgents had regrouped after French airstrikes and embedded themselves among the population of Diabaly, hiding in the mud and brick houses in the battle zone and thwarting attacks by French warplanes to dislodge them.
"They are in the town, almost everywhere in the town," said Bekaye Diarra, who owns a pharmacy in Diabaly, which remained under the control of insurgents. "They are installing themselves."
Benco Ba, a parliamentary deputy there, said residents were fearful of the conflict that had descended on them. "The jihadists are going right into people's families," he said. "They have completely occupied the town. They are dispersed. It's fear, " he said, as it became
clear that airstrikes alone will probably not be enough to root out these battle-hardened insurgents, who know well the harsh grassland and desert terrain of Mali.
Containing the rebels' southern advance toward Bamako is proving more challenging than anticipated, French military officials have acknowledged. And with the Malian Army in disarray and no outside African force yet assembled, displacing the rebels from the country altogether appears to be an elusive, long-term challenge.
The jihadists were "dug in" at Diabaly, Defense Minister Le Drian said Tuesday at a news conference. From that strategic town, they "threaten the south," he said, adding: "We face a well-armed and determined adversary."
Mr. Le Drian also acknowledged that the Malian Army had not managed to retake the town of Konna, whose seizure by the rebels a week ago provoked the French intervention. "We will continue the strikes to diminish their potential," the minister said.
Adam Nossiter reported from Bamako, Mali, Alan Cowell from Paris and Eric Schmitt from Washington. Reporting was contributed by Steven Erlanger and Scott Sayare from Paris, Julia Werdigier from London, and Elisabeth Bumiller from Madrid.