In the hours before the no-fly zone over Libya went into effect, Gaddafi sent warplanes, tanks and troops into Benghazi, the rebel capital and first city to fall to the rebellion that began Feb. 15. Then the government attacks appeared to go silent.
French President Nicolas Sarkozy said after an emergency summit in Paris that French jets were already targeting Gaddafi's forces. The 22 participants in Saturday's summit agreed to do everything necessary to make Gaddafi respect a UN Security Council resolution on Thursday demanding a cease-fire, Sarkozy said.
"Our consensus was strong, and our resolve is clear. The people of Libya must be protected, and in the absence of an immediate end to the violence against civilians our coalition is prepared to act, and to act with urgency," President Barack Obama said in Brasilia, Brazil, on the first day of a three-country Latin American tour.
The rebels, who have seen their advances into western Libya turn into a series of defeats, said they had hoped for more, sooner from the international community, after a day when crashing shells shook the buildings of Benghazi and Gaddafi's tanks rumbled through the university campus.
"People are disappointed, they haven't seen any action yet. The leadership understands some of the difficulties with procedures but when it comes to procedures versus human lives the choice is clear," said Mustafa Gheriani, a spokesman for the opposition.
"People on the streets are saying where are the international forces? Is the international community waiting for the same crimes to be perpetrated on Benghazi has have been done by Gaddafi in the other cities?"
A doctor said 27 bodies had reached hospitals by midday. As night fell, though, the streets were quiet.
Libyan state television showed Gaddafi supporters converging on the international airport and a military garrison in Tripoli, and the airport in Gaddafi's hometown of Sirte, in an apparent attempt to deter bombing.
In an open letter, Gaddafi warned: "You will regret it if you dare to intervene in our country."
In Paris, US Secretary of State Hillary Rodham Clinton said Gaddafi's government had lost all legitimacy and lied about the cease-fire.
"We have every reason to fear that left unchecked, Gaddafi will commit unspeakable atrocities," she said.
Saturday's emergency meeting involved 22 leaders and top officials, including Arab League Secretary-General Amr Moussa and UN Secretary-General Ban Ki-Moon and the foreign ministers of Jordan, Morocco and the United Arab Emirates. It was the largest international military action since the beginning of the Iraq war, launched almost exactly eight years ago.
Earlier Saturday, a plane was shot down over the outskirts of Benghazi, sending up a massive black cloud of smoke. An Associated Press reporter saw the plane go down in flames and heard the sound of artillery and crackling gunfire.
Before the plane went down, journalists heard what appeared to be airstrikes from it. Rebels cheered and celebrated at the crash, though the government denied a plane had gone down - or that any towns were shelled on Saturday.
The fighting galvanised the people of Benghazi, with young men collecting bottles to make petrol bombs. Some residents dragged bed frames and metal scraps into the streets to make roadblocks.
"This city is a symbol of the revolution, it's where it started and where it will end if this city falls," said Gheriani.
But at Jalaa hospital, where the tile floors and walls were stained with blood, the toll was clear.
"There are more dead than injured," said Dr. Ahmed Radwan, an Egyptian who had been there helping for three weeks.
Jalaa's Dr. Gebreil Hewadi, a member of the rebel health committee, said city hospitals had received 27 bodies.
At a news conference in the capital, Tripoli, the government spokesman read letters from Gaddafi to Obama and others involved in the international effort.
"Libya is not yours. Libya is for the Libyans. The Security Council resolution is invalid," he said in the letter to Sarkozy, British Prime Minister David Cameron, and UN Secretary-General Ban Ki-Moon.
To Obama, the Libyan leader was slightly more conciliatory: "If you had found them taking over American cities with armed force, tell me what you would do."
In a joint statement to Gadhafi 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 the cities of Misrata, Ajdabiya and Zawiya.
It also called for the restoration of water, electricity and gas services in all areas. It said Libyans must be able to receive humanitarian aid or the "international community will make him suffer the consequences" with military action.
Foreign Minister Moussa Koussa said that Libyan officials had informed the UN and the Security Council that the government was holding to the cease-fire it had announced Friday and called for a team of foreign observers to verify that.
"The nation is respecting all the commitments put on it by the international community," he said, leaving the podium before answering any questions about Benghazi.
In the course of the rebellion, Libya has gone from a once-promising economy with the largest proven oil reserves in Africa to a country in turmoil. The foreign workers that underpinned the oil industry have fled; production and exports have all but ground to a halt; and its currency is down 30 per cent in just two weeks.
The oil minister, Shukri Ghanem, held a news conference calling on foreign oil companies to send back their workers. He said the government would honour all its contracts.
"It is not our intention to violate any of these agreements and we hope that from their part they will honour this agreement and they will send back their work forces," he said.
Italy, which had been the main buyer for Libyan oil, offered the use of seven air and navy bases already housing U.S., NATO and Italian forces to enforce the no-fly zone over Libya.
Italy's defence minister, Ignazio La Russa, said Saturday that Italy wasn't just "renting out" its bases for others to use but was prepared to offer "moderate but determined" military support.
A French fighter jet fired Saturday on a Libyan military vehicle, the first reported offensive action in the international military operation against Gaddafi's forces, French defence Ministry spokesman Thierry Burkhard said.
Warplanes from the United States, Canada, Denmark arrived at Italian air bases Saturday as part of an international military buildup. Germany backed the operation but isn't offering its own forces.
British Prime Minister David Cameron said after the summit: "The time for action has come, it needs to be urgent."