French President Francois Hollande raised the country's domestic terror threat level on Saturday following military operations in Mali and Somalia against Islamist forces.

French aircraft and troops are backing soldiers in Mali who are trying to push back Islamist offensives; in Somalia, French commandos launched a failed, deadly raid to rescue an intelligence agent held hostage there for three years.

In Mali, French airstrikes overnight drove back Islamist rebels from a key city and destroyed a militant command center, the French defense minister said on Saturday, as West African nations authorized the immediate deployment of troops to the country.

The Al-Qaida-linked militants, who have carved out their own territory in the lawless desert region of northern Mali over the past nine months, recently pressed closer to a major base of the Malian army, dramatically raising the stakes in the battle for the vast West African nation.

"The threat is a terrorist state at the doorstep of France and Europe," said French Defense Minister Jean-Yves Le Drian.

The French operation, which started Friday in the former French colony, came after an appeal for help from Mali's president. The fighting involved hundreds of French troops and overnight airstrikes on three rebel targets, said Le Drian. He said a rebel command center outside the key city of Konna was destroyed.

Adm. Edouard Guillaud said a French helicopter had been downed and that the pilot died of his wounds while he was being evacuated to safety.

A military official in Mali said Islamist militants were driven out of Konna, but that the city captured by the extremists earlier this week was not yet under government control.

"We are doing sweeps of the city to find any hidden Islamist extremist elements," said Lt. Col. Diarran Kone. "The full recovery of the city is too early to determine, as we do not yet control the city."

Sanda Abou Mohamed, spokesman for Islamist group Ansar Dine, told The Associated Press he could not confirm if his fighters were still in Konna.

In a statement released Saturday, ECOWAS commission president Kadre Desire Ouedraogo said the bloc had authorized the immediate deployment of troops to Mali. He said they made the decision "in light of the urgency of the situation."

ECOWAS did not say how many troops would be sent to Mali or when they would arrive. It also did not specify which countries from the 15-nation bloc would be providing the forces.

ECOWAS has been talking for months about a military operation to oust the Islamists from northern Mali. While the UN approved a plan for deployment, it had not been expected until September.

Burkina Faso's Minister of Foreign Affairs Djibril Bassole said on Saturday that his country would send 500 troops into neighboring Mali. He said the parliament will meet in the next couple of days to solidify the details.

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. In recent months, however, the terrorist group and its allies have taken advantage of political instability, taking territory they are using to stock weapons and train forces.

Turbaned fighters control major towns in the north, carrying out amputations in public squares just as the Taliban did. And as in Afghanistan, they are flogging women for not covering up. Since taking control of Timbuktu, they have destroyed seven of the 16 mausoleums listed as world heritage sites.

French President Francois Hollande said the "terrorist groups, drug traffickers and extremists" in northern Mali "show a brutality that threatens us all." He vowed that the operation would last "as long as necessary."

France said it was taking the action in Mali at the request of President Dioncounda Traore, who declared a state of emergency because of the militants' advance.

Hollande has said the operation is aimed in part at protecting the 6,000 French citizens in Mali, where seven of them already are being held captive.

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

Commando killed in Somalia raid

Separately, a French commando raid in Somalia to free a captive intelligence agent ended in the deaths of 17 Islamists and a French soldier. France said the hostage also died in the failed rescue, but the man's captors denied he had been killed and claimed Saturday to have seized a second soldier.

Confusion surrounded early reports of the botched rescue of the French agent, known by his code-name Denis Allex. He was captured in the east African country on July 14, 2009, and last seen in a video released in October pleading for the French president to help him.

But it was clear that a dangerous raid the French defense minister said was planned with the utmost care had gone horribly wrong.

Le Drian said Allex was killed by his captors and that one French soldier was missing and one dead, along with 17 Islamists. The Defense Ministry earlier said two commandos were killed in the fighting in the Somali town of Bulomarer.

"It was an extremely dangerous mission," Le Drian said. "Everything indicates Denis Allex was killed."

The militant Islamist group Al-Shabab, which held Allex for more than three years, said on Saturday that he remained alive and in its custody, as was a new captive ¬ a French commando wounded in fighting.

Le Drian said the operation in Somalia was unrelated to the French offensive overnight in Mali.

Residents of Bulomarer described hearing explosions and gunfire from what they called an Al-Shabab base. An Al-Shabab official said that fighting began after helicopters dropped off French soldiers.

"Five helicopters attacked a house in the town. They dropped soldiers off on the ground so that they could reach their destination ... but fighting has broken out," he said on condition of anonymity because he was not authorized to speak to the media.

The French attack was swift and loud, residents said.

"We heard a series of explosions followed by gunfire just seconds after a helicopter flew over the town," Mohamed Ali, a resident of Bulomarer, told The Associated Press by telephone. "We don't know exactly what happened, but the place was an Al-Shabab base and checkpoint."

The Al-Shabab official said some soldiers were killed, but the group held only one dead French soldier. Later, the Islamist group released a statement saying that Allex "remains safe and far from the location of the battle." It said there would be a verdict in his case in two days.

Allex was kidnapped from a hotel in Mogadishu, Somalia, on July 14, 2009, with a colleague who later escaped. They were in Somalia to train government forces, which are fighting Islamist militiamen.

In 2009, a Frenchman held hostage by pirates off the Somali coast was killed in the crossfire during a commando rescue on his captive sailboat. The man's family was rescued.

And in 2011, two French hostages kidnapped in Niger were killed by their captors as French troops closed in for a rescue.