Paris:
French warplanes swooped over the heart of Libya's uprising on Saturday as top officials from the United States, Europe and the Arab world launched a risky military operation to protect civilians from attacks by Libyan leader Moammar Gaddafi's forces.
Mirage and Rafale fighter jets are flying over Benghazi and could strike Gaddafi's tanks later Saturday, a senior French official told The Associated Press.
The official said the jets are flying over the opposition stronghold and its surroundings. The official spoke on condition of anonymity because of the sensitivity of the operation.
Libyan government troops stormed into Benghazi on Saturday, apparently ignoring a proclaimed cease-fire. The incursion into Benghazi and other cities by Gaddafi's forces could vastly complicate any international intervention, by allowing the troops to mingle in with the population - making airstrikes against them difficult.
The United States, Britain, France and 19 other participants in an emergency summit in Paris on Saturday "agreed to put in place all the means necessary, in particular military" to make Gaddafi respect a U.N. Security Council resolution Thursday demanding a cease-fire, French President Nicolas Sarkozy said.
"In accord with our partners, our air forces will oppose any aggression by Col. Gaddafi's airplanes against the population of Benghazi. Already, our planes are preventing air attacks against the city. Already, other French planes are ready to intervene against tanks that would threaten unarmed civilians," Sarkozy said in a brief declaration.
U.S. Secretary of State Hillary Clinton was also at Saturday's summit and was expected to speak later Saturday.
British Prime Minister David Cameron said after the summit: "The time for action has come, it needs to be urgent."
Several countries clarified their possible participation in any armed intervention, laying out how long it would take for national forces to join in air strikes or surveillance over flights.
France, Britain and the United States had warned Gaddafi Friday that they would resort to military means if he ignored the U.N. resolution.
Sarkozy acknowledged the risks of the operation, and insisted it did not amount to an international occupation force.
"There is still time for Col. Gaddafi to avoid the worst by complying without delay and without reservations to all the demands of the international community. The door of diplomacy will reopen at the moment when the aggressions cease," Sarkozy said.
A communiqué from the summit participants, referring to the U.N. Security Council resolution, said: "Our commitment is for the long term: we will not let Colonel Gaddafi and his regime go on defying the will of the international community and scorning that of his people.
"We will continue our aid to the Libyans so that they can rebuild their country, fully respecting Libya's sovereignty and territorial integrity."
With the leaders meeting in Paris, the international military build-up mounted in the region. Six Danish F-16 fighter jets landed Saturday at the U.S. air base in Sicily, and American F-18s and Canadian CF-18 Hornets were in the region.
A senior U.S. official said Clinton has been following developments in Libya closely, and that "everybody recognizes the urgency of the situation."
"We've made clear what our expectations are and we have also made clear that the international community is prepared to act if (Gaddafi) doesn't meet those expectations," said the official, speaking on condition of anonymity because of a delicacy of the situation.
France, Britain and the United States were among the major backers of a muscular U.N. Security Council resolution passed Thursday that authorizes a no-fly zone over Libya and "all necessary measures" to protect civilians.
Arab League Secretary-General Amr Moussa and U.N. Secretary-General Ban Ki-Moon were in Paris along with Qatar's emir Sheikh Hamad Bin Khalifa Al Thani and foreign ministers of Jordan, Moroccan and the United Arab Emirates.
Italy has offered the use of seven air and navy bases already housing U.S., NATO and Italian forces. Sigonella's size and close proximity to Libya makes it a key staging point.
Canada is also readying for involvement. "While Canada supports quick action, Canadian fighter jets have just reached the region and will require two days to prepare for any missions," said Andrew MacDougall, spokesman for Prime Minister Stephen Harper.
NATO's top decision-making body met Saturday to review military plans for a no-fly zone over Libya. The consultations were adjourned soon after they convened to await the results of the summit in Paris.
Officials said military staffs were putting the final touches on rules of engagement and on plans to deploy fighter-bombers, tankers, helicopters and surveillance planes to several air bases along Europe's southern rim. A NATO diplomat said it was likely that any such operation would be controlled from NATO's command centre in Naples.
The North Atlantic Council must have the agreement of all 28 its members in issue the order to launch the operation.
In a joint statement to Gaddafi late Friday, the United States, Britain and France -- backed by unspecified Arab countries -- called on Gaddafi to end his troops' advance toward Benghazi, and pull them out of Misrata, Adjadbiya and Zawiya, and called for the restoration of water, electricity and gas services in all areas. It said Libya's population must be able to receive humanitarian aid.
The United States has a host of forces and ships in the area, including submarines, destroyers, amphibious assault and landing ships. U.S. officials have not specified the possible American role -- although Obama said Friday that no U.S. ground troops would be involved.
NATO surveillance AWACS planes flying off the Libyan coast are already providing 24-hour coverage of the situation in the air and on the battlefields. Analysts said no-fly zone aircraft would be flying from NATO bases such as in Sigonella, Sicily, Aviano in northern Italy, Istres in southern France, and Ventiseri-Solenzara in Corsica.