Nineteen US planes, including three B2 stealth bombers, took part in early morning raids Sunday, the Germany-based US Africa Command said.
B-2 stealth bombers dropped 40 bombs on a major Libyan airfield in an attempt to destroy much of the Libyan Air Force, other US military officials said.
On the ground, AFP correspondents and rebels said dozens of Libyan government military vehicles, including tanks, were destroyed on Sunday morning in air strikes west of Benghazi.
The bodies of African fighters in khaki-coloured uniforms could be seen amid a pile of smashed up tanks and burned artillery cannons at a site 35 kilometres (20 miles) from Benghazi, the sources said.
But as Libya reported at least 48 dead in the West's air strikes, medics in Benghazi said 85 civilians and rebels were killed in fighting with Kadhafi's forces on Friday and Saturday.
"We promise you a long, drawn-out war with no limits," said the Libyan leader, who was speaking on state television for a second straight day without appearing in front of camera.
The leaders of Britain, France and the United States will "fall like Hitler... Mussolini," warned the strongman of oil-rich Libya who has ruled for four decades but been confronted with an armed uprising since mid-February.
"America, France, or Britain, the Christians that are in a pact against us today, they will not enjoy our oil," he said. "We do not have to retreat from the battlefield because we are defending our land and our dignity."
State television showed footage of hundreds of Kadhafi supporters who it said had gathered earlier to serve as human shields at Bab al-Aziziyah and at the capital's international airport.
Russia expressed regret over the attacks and said Resolution 1973 was "adopted in haste," while the African Union, which has opposed military action, on Sunday called for an "immediate stop" to all attacks.
China also voiced regret over the air strikes, saying it opposed the use of force in international relations.