Coalition forces stepped up attacks on the military assets of Libyan leader Moammar Gadhafi and worked to enforce an arms embargo in the war-torn country, while NATO agreed to lead efforts to enforce the no-fly zone.

NATO's secretary-general announced the agreement late Thursday, saying the alliance's operation would operate separately from coalition bombing raids.

"At this moment there will still be a coalition operation and a NATO operation," Fogh Rasmussen said in Brussels.

"We are considering whether NATO should take on the broader responsibility in accordance with the UN Security Council resolution," he added. "But that decision has not been reached yet."

Until now, the U.S. has been leading the international operation, which includes military contributions from European countries such as France and Britain, as well as Canada and the tiny Arabian Gulf nation of Qatar.

By comparison, NATO's 28 members include Canada, the United States, Iceland and 25 European states. Rasmussen said the NATO operation could be up and running within here days.

The alliance had been struggling to overcome differences over the role it should play in the Libya war. Earlier on Thursday, Turkey's state-run TV reported earlier in the day that the country's objections to NATO's role in the operation had been addressed, paving the way for the organization to take the helm.

Meanwhile, coalition forces continued to attack the military assets of Libyan leader Moammar Gadhafi, and stepped up efforts to prevent mercenaries or weapons from entering the war-torn North African country.

In overnight raids, French warplanes hit a base that lies about 250 kilometres south of the Libyan coastline.

Libyan Deputy Minister Khaled Kaim said the "military compound at Juffra" was among the targets hit before dawn.

The strike appeared to be aimed at dismantling a landing point for aircraft that could bring deadly weapons or mercenaries into Libya, which Gadhafi could use in his weeks-long battle with rebels who are fighting for his ouster.

There were also reports that French warplanes also shot down a Libyan plane that was in flight near the coastal city of Misrata.

At the Pentagon, U.S. Navy Vice Adm. Bill Gortney said the U.S. would continue to provide "enabling capabilities to enforce the UN mandate" after a new command structure was in place.

He told reporters that so far, coalition had forced Gadhafi forces to withdraw from the eastern rebel-held cities of Benghazi and Ajdabiya. But he said Gadhafi troops continued "operations" around Misrata and Zintan.

"We will continue to apply the pressure we can through strikes on their logistics, command communications and weapons capabilities to compel them to stop killing their own people," Gortney said.

Along Libya's Mediterranean coast, NATO ships were patrolling for any ships that could be trying to bring in foreign fighters or weapons.

Vice Adm. Rinaldo Veri said that NATO does not have enough ships to patrol the entire Libyan coast at the moment, but will within a few days.

He said NATO was ready to engage any ships that don't voluntarily submit to inspections.

"If they should find resistance, the use of force is necessary," Veri said.

Propaganda war

A defiant Gadhafi has stated his expectation of victory against the rebels and the coalition forces, whom he has described as outsiders and "crusaders."

Libyan state television showed images of charred bodies of people the government claimed were killed by coalition airstrikes.

The rebels have accused Gadhafi's forces of taking bodies from the morgue and pretending they are civilian casualties.

CTV's Ben O'Hara-Byrne said that Gadhafi is putting out these messages in an attempt to try to win support from Libyans and erode support for the coalition's actions against his regime.

"This all part of a very intense propaganda war being waged by Libya as its own military forces are being systematically destroyed by coalition air strikes," O'Hara-Byrne told CTV News Channel from Cairo on Thursday.

Gortney said that there have been no confirmed reports of coalition strikes causing civilian deaths.

"Indeed, the only civilian casualties we know are for certain are the ones that the Libyan government itself has caused," he told reporters Thursday afternoon.

Mounting damage to Libyan targets

Since Saturday, the coalition forces have pounded Libyan military targets with scores of cruise missiles, bombings and airstrikes, which the UN Security Council authorized after Gadhafi launched attacks against anti-government protesters who have been fighting for his ouster.

The punishing airstrikes have wiped out Gadhafi's air force and sent his ground forces into retreat from key conflict zones.

On Wednesday, Rear Adm. Gerard Hueber, a top U.S. officer in the campaign in Libya, told reporters that the Gadhafi regime had not attempted to put planes in the sky for at least a day, after coalition bombardments essentially defeated the Libyan air force.

"Those aircraft have either been destroyed or rendered inoperable," Hueber said.

On the ground, Gadhafi's troops pulled their tanks out of the western cities of Misrata and Zintan after coalition airstrikes on Wednesday, while also facing some military pressure from rebel fighters in the latter city.

Zintan resident Ali al-Azhari said the rebels had been fighting Gadhafi's forces for the past five days, before forcing most of the regime troops to leave the city on Wednesday.

Al-Azhari said a captured Libyan military officer told the rebels he was ordered "to turn Zintan into a desert to be smashed and flattened."

Some Libyan tanks returned to Misrata on Thursday, but periodically rolled back as coalition airstrikes were detected.

A 42-year-old Misrata doctor told the Associated Press that some Gadhafi troops remained inside the city.

"When the allies' planes were seen flying in the sky, the shelling stopped and the tanks fled," he said. "We still have to deal with snipers in the main street in Misrata and try to warn people to stay away from it."

A U.S. defence official said Thursday that coalition forces hit an ammunition bunker near Misrata and Libyan forces stated south of Benghazi.

No consensus on when, if Gadhafi regime will fall

Despite the devastation to Gadhafi's air forces and the depletion of his capabilities on the ground, there is still no consensus on when his regime will fall, if the long-time leader can be forced from power, or how long the coalition will maintain its military presence within Libya.

French Foreign Minister Alain Juppe told reporters Thursday that he believed the military operation against Gadhafi could last days or weeks, but not months.

But Russian diplomat Vladimir Chamov predicted that Gadhafi could hold off coalition forces for months, if necessary.

Charmov, who until recently served as Russia's ambassador to Libya, also said that Gadhafi still holds broad public support and will not step down.

Speaking in Cairo on Wednesday, U.S. Defence Secretary Robert Gates said he could not predict how long the international enforcement of a no-fly zone over Libya would continue.

With files from The Associated Press