The French air force destroyed Libyan tanks and armored vehicles on Saturday, the first shots fired in a U.N.-mandated military intervention to protect civilians from attacks by Muammar Gaddafi’s forces.

A French defense ministry official said “a number of tanks and armored vehicles” were destroyed in the region of Benghazi, with initial action focusing on stopping Gaddafi’s forces from advancing on the rebels’ eastern stronghold.

Gaddafi’s troops pushed into the outskirts of Benghazi on Saturday after a unilateral ceasefire declared by his government failed to materialize, prompting leaders meeting in Paris on Saturday to announce the start of military intervention.

“Those taking part agreed to put in place all necessary means, especially military, to enforce the decisions of the United Nations Security Council,” French President Nicolas Sarkozy said after meeting Western and Arab leaders.

Sarkozy said an operation supported by France, Britain, the United States and Canada, and backed by Arab nations, would continue unless the Libyan leader ceased fire.

“Colonel Gaddafi has made this happen,” British Prime Minister David Cameron told reporters after the meeting. “We cannot allow the slaughter of civilians to continue.”

Some analysts have questioned the strategy for the military intervention, fearing western forces might be sucked into a long civil war despite their current insistence they have no plans to send ground troops to Libya.

Canadian Prime Minister Stephen Harper suggested that outside powers hoped their intervention would be enough to turn the tide against Gaddafi and allow Libyans to force him out.

“It is our belief that if Mr. Gaddafi loses the capacity to enforce his will through vastly superior armed forces, he simply will not be able to sustain his grip on the country.”

SUPPORTERS GATHER AT GADDAFI COMPOUND

Gaddafi has said Western powers had no right to intervene.

“This is injustice, this is clear aggression,” government spokesman Mussa Ibrahim quoted Gaddafi as saying in a letter to France, Britain and the United Nations. “You will regret it if you take a step toward interfering in our internal affairs.”

The Libyan government blamed the rebels, who it says are members of al Qaeda, for breaking a ceasefire around Benghazi.

In Tripoli, several thousand people gathered at the Bab al-Aziziyah palace, Gaddafi’s compound that was bombed by U.S. warplanes in 1986, to show their support.

“There are 5,000 tribesmen that are preparing to come here to fight with our leader. They better not try to attack our country,” said farmer Mahmoud el-Mansouri.

“We will open up Libya’s deserts and allow Africans to flood to Europe to blow themselves up as suicide bombers.”

France and Britain have taken a lead role in pushing for international intervention in Libya and the United States — after embarking on wars in Afghanistan and Iraq — has been at pains to stress it is supporting, not leading the operation.

Clinton said the United States would bring its “unique capabilities” to bear to help its European and Canadian allies in enforcing the U.N. resolution passed on Thursday.

THOUSANDS FLEE BENGHAZI

A large plume of black smoke rose from the edge of Benghazi mid-afternoon, live television pictures showed, but it was not clear what was causing the fire.

Residents set up make-shift barricades with furniture, benches, road signs and even a barbecue in one case at intervals along main streets. Each barricade was manned by half a dozen rebels, but only about half of those were armed.

Hundreds of cars full of refugees fled Benghazi toward the Egyptian border after the city came under a bombardment overnight. One family of 13 women from a grandmother to small children, rested at a roadside hotel.

“I’m here because when the bombing started last night my children were vomiting from fear,” said one of them, a doctor. “All I want to do is get my family to a safe place and then get back to Benghazi to help. My husband is still there.”

In the besieged western city of Misrata, residents said government forces shelled the rebel town again on Saturday and they were facing a humanitarian crisis as water supplies had been cut off for a third day.

“I am telling you, we are scared and we are alone,” a Misrata resident, called Saadoun, told Reuters by telephone.

As explosions shook Benghazi on Saturday morning, rebels said they were forced to retreat from the outskirts of the city, but later claimed victory after holding back the advance.

“We revolutionaries have taken control of four tanks inside Benghazi. Rebel forces have pushed Gaddafi’s forces out of Benghazi,” said Nasr al-Kikili, a lawyer who works for the rebel media center in Benghazi, as crowds celebrated by firing guns in the air and parading on top of a tank.

A warplane was shot down over Benghazi. Opposition activist Azeldin al-Sharif said rebel forces had brought their own plane down by mistake.

Al Jazeera said there were 26 dead and more than 40 wounded in Jala hospital in Benghazi, without giving further details.

U.S. President Barack Obama has made clear any military action would aim to change conditions across Libya, rather than just in the rebel-held east, by calling on Gaddafi’s forces to pull back from the western cities of Zawiyah and Misrata as well as from the east.

“Gaddafi must stop his troops from advancing on Benghazi, pull them back from Ajdabiya, Misrata and Zawiyah, and establish water, electricity and gas supplies to all areas. Humanitarian assistance must be allowed to reach the people of Libya,” Obama said on Friday.

-Reauters