Amid the intensified fighting, the international community stepped up moves to isolate the longtime Libyan leader.
U.S. Defense Secretary Robert Gates said he ordered two ships into the Mediterranean, including the amphibious assault ship USS Kearsarge, and he is sending 400 Marines to the vessel to replace some troops that left recently for Afghanistan.
Military leaders weighing a no-fly zone over Libya said it would be a complex task that would require taking out Gadhafi's air defenses, and Russia's top diplomat dismissed the idea as "superfluous" and said world powers should focus on sanctions.
Gadhafi's son, Seif al-Islam, warned Western forces not to take military action against Libya and said the country is prepared to defend itself against foreign intervention.
"If they attack us, we are ready," he told Sky News, adding that the Gadhafis are ready to implement reforms.
Facing an unprecedented challenge to his 41-year rule, Gadhafi's regime has launched the bloodiest crackdown in a wave of uprising against authoritarian rulers in the Middle East. Gadhafi has already lost control of the eastern half of the country but still holds Tripoli and other nearby cities.
An exact death toll has been difficult to obtain in the chaos, but a medical committee in the eastern city of Benghazi, where the uprising began on Feb. 15, said at least 228 people had been killed, including 30 unidentified bodies, and 1,932 wounded.
U.N. Secretary General Ban Ki-moon has cited reports that perhaps 1,000 have died in Libya.
Secretary of State Hillary Rodham Clinton told Congress that the U.S. must lead an international response to the crisis, including expanding already tough financial and travel sanctions against Gadhafi, his family and confidants and possibly imposing a no-fly zone over Libya.
"In the years ahead, Libya could become a peaceful democracy, or it could face protracted civil war. The stakes are high," she said.
Gadhafi's regime has retaken at least two towns and threatened a third, while rebels repulsed attacks on three other key areas - Misrata to the east, Zawiya to the west, and the mountain town of Zintan to the south of the capital.
One of those retaken was the strategic mountain town of Gharyan, the largest in the Nafusa Mountains, which overlooks Tripoli, a resident said, speaking on condition of anonymity for fear of government retaliation. The town fell after dark Friday in a surprise attack, and the government troops detained officers who defected to the rebels and drew up lists of wanted protesters and started searching for them, the resident added.
Gadhafi supporters also have said they were in control of the city of Sabratha, west of Tripoli, which has seemed to go back and forth between the two camps in the past week.
But witnesses in Zawiya, 30 miles (50 kilometers) west of the capital, said rebels shouted "Allahu akbar (God is great) for our victory," and carried an air force colonel who had just defected after six hours of overnight gunbattles failed to dislodge anti-Gadhafi forces who control the city.
"We were worried about air raids but that did not happen," said one resident, who spoke on condition of anonymity for fear of reprisals.
The Zawiya rebels have tanks, machine guns and anti-aircraft guns. They beat back pro-Gadhafi troops, armed with the same weapons, who attacked from six directions. There was no word on casualties.
In Misrata, 125 miles (200 kilometers) east of Tripoli, pro-Gadhafi troops who control part of an air base on the city's outskirts tried to advance Monday. But they were repulsed by opposition forces, who included residents with automatic weapons and defected army units allied with them, one of the opposition fighters said.
No casualties were reported and the fighter claimed that his side had captured eight soldiers, including a senior officer.
The opposition controls most of the air base, and the fighter said dozens of anti-Gadhafi gunmen have arrived from farther east in recent days as reinforcements.
In Zintan, 75 miles (120 kilometers) south of Tripoli, residents said an attack by pro-Gadhafi forces Monday night was the second since the city fell in rebel hands late last month. But, they added, Gadhafi's loyalists were bringing in reinforcements.
One person in Zwara, which fell to anti-government forces days ago, said guards were posted at every sensitive building and all the entrances to the town.
"We are threatened every day by pro-Gadhafi forces," the nervous Zwara resident said, adding that a pro-Gadhafi figure met with the town's leaders a few days ago and told them they had "a choice" to go back in to orbit "and he will forget what happened, or else he is going to attack us with military force. He even offered us money."
One sergeant in the Libyan army who is of Tuareg ethnicity and is fighting on Gadhafi's side said the military is divided.
"Us foreigners, we don't have much choice. We have to support Gaddafi," he said in a telephone interview with The Associated Press in Mali. "It because of him we are here."
He added that everyone who supports Gadhafi has not been watching any foreign news.
"There is nothing that's going to convince Gaddafi to quit," the soldier said. "The only way Gaddafi is going to go is if someone puts a bullet in his head, and I can't imagine that. The soldiers who are close to him would never let it happen."
Many young citizens of Mali and Niger who flocked to Libya in the 1970s and 1980s were ethnic Tuaregs and were recruited into an "Islamic Legion" modeled on the French Foreign Legion.
With fears high that Gadhafi could wage airstrikes against his own people, the European Union and the United States have raised the possibility of a no-fly zone over Libya - a tactic used successfully in northern Iraq and Bosnia.
But Russian Foreign Minister Sergey Lavrov called the idea "superfluous" and said world powers must instead focus on fully using the sanctions the U.N. Security Council approved over the weekend. Russia is a veto-wielding member of the Security Council.
Susan Rice, the U.S. ambassador to the United Nations, meanwhile, urged Gadhafi to consider exile, saying she's worried the African nation could plummet into a "humanitarian disaster."
"It's important that he get off the stage," Rice said told CBS on "The Early Show."
More than 140,000 people have streamed into Tunisia and Egypt, and the situation at the Tunisian border has reached a "crisis point," with up to 75,000 people gathering in just nine days said U.N. refugee agency spokeswoman Melissa Fleming. Many have returned to their homes in Tunisia and Egypt.
But thousands of Vietnamese and Bangladeshis at the Libyan side of border with Tunisia are "in urgent need of food, water and shelter," said Jemini Pandya, a spokeswoman for International Organization for Migration. Nepalese, Ghanaians and Nigerians are also sleeping unprotected at the borders, she added.
Thousands of foreigners - many of them Egyptians - have been stranded for at least a week at Tripoli's airport, where they have little food, no shelter and face mistreatment by Libyan authorities.
The workers were willing to stay in their homes across in various cities, including Tripoli, but said they were attacked by locals who stole their money, cell phones and threatened to shoot them unless they left. They said they came to the airport, thinking it would be safe, but have endured harsh conditions since arriving, unable to enter the terminal or even a bathroom at a mosque, without paying.
The grass in front of the airport terminal were littered with clothes, shoes, sheets, cans and garbage.
Mohammed Shahat, 26, who works in a ceramics company in Zawiya, said he has camped at the airport for a week.
"I was told that I can enter the terminal but first I have to pay 200 dinars (about $160). I paid, but then they took my passport and kicked us out," he said.
On Tuesday, Gadhafi's regime sought to show that it was the country's only legitimate authority and that it continued to feel compassion for areas in the east that fell under the control of its opponents.
A total of 18 trucks loaded with rice, flour, sugar and eggs left Tripoli for Benghazi, the country's second-largest city 620 miles (1,000 kilometers) east of the capital. Also in the convoy were two refrigerated cars carrying medical supplies.
People in opposition-controlled areas were running low on medical supplies.
Dr. Abdullah Gleissa, head of surgery at Jalaa Hospital in Benghazi said that while it had enough basic medical supplies, it was short of some instruments, narcotics and personnel skilled in certain types of surgery.
"We are still clearing up cases that have been waiting for operations," he said.
The battles were not limited to Libyan cities and towns.
Libyan state television channel Jamahiriya-2 said on a news ticker that jamming of unknown origin had temporarily affected broadcasts of the main state-controlled channel, Jamahirya 1. The main channel was back on the air Tuesday night.
The news website Quryna, which has ties to Gadhafi's son, Seif al-Islam, has been down for days. On Tuesday morning, it bore a monarchist flag of the pre-Gahdafi era and a statement saying the site had been hacked by the rebels. Later, it opened to a mostly blank page that read: "This Account Has Been Suspended."