Tripoli, Libya (CNN) -- Loud explosions and heavy anti-aircraft gunfire rang out early Wednesday in the Libyan capital, hours after the nation's defiant leader vowed to win his battle with coalition forces.
The sources of the blasts and gunfire in western Tripoli were unclear, but there is a large military base in the area.
U.S. officials said while coalition forces conducted airstrikes Tuesday night, they did not "specifically target anything" in the capital.
Four days of military strikes by French, Britain and the United States' forces have rendered Libyan leader Moammar Gadhafi's long-range air defenses and his air force largely ineffective, military officials have said.
But on the ground, forces loyal to the ruler continued their assault on towns with a rebel presence.
"Tanks and snipers are in the center of the city," a witness said early Wednesday, about the western port city of Misrata. "The people are living in a state of fear. Electricity has been cut off, water has been cut off."
The witness said hospitals are overflowing.
"Injured people are sleeping on the floor," he said. "Misrata needs help."
The death toll from the clashes between Gadhafi forces and rebels in the city stands at 90 over the past five days, according to medical officials.
An opposition leader said they have submitted requests for weapons to various nations to help the embattled city.
"Misrata is destroyed and they need weapons," Gen. Abdul Fatah Younis told CNN. "We try to send them weapons, but of course they were all light weapons. There were no heavy weapons."
Younis, a former interior minister, quit the government and now leads the opposition forces.
The international airstrikes against Libyan military positions began over the weekend after Gadhafi defied a United Nations-mandated cease-fire. The strikes are intended to help establish a no-fly zone.
But even after days of having his military bases pounded with missiles, Gadhafi remained defiant.
"We will not give up," he said Tuesday on state media as supporters waved green flags. "They will not terrorize us. We are making fun of their rockets. The Libyans are laughing at these rockets. We will defeat them by any method."
Late Monday, coalition forces suffered a minor setback when a U.S. fighter jet malfunctioned and crashed near Benghazi in eastern Libya.
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After the crash, the two crew members parachuted out and landed in different places. A U.S. rescue crew picking up the pilot dropped two 500-pound laser-guided bombs after it saw a crowd moving toward him.
An investigation is under way after reports surfaced that some Libyans were injured by shrapnel during the rescue.
Rebels recovered the second crew member and treated him with "respect and dignity" until coalition forces reached him, U.S. Navy Adm. Samuel Locklear III said.
Violence has raged in Libya following protests calling for democracy and demanding an end to Gadhafi's almost 42-year rule.
Protesters have been met by force from the Gadhafi regime, and numerous world leaders have denounced the killings of civilians.
Locklear said the ruler is violating the U.N. Security Council resolution by unleashing his forces on civilians, and multinational strikes will continue until he stops the attacks.
The international operation has targeted air defense sites and command centers, but Gadhafi has not been targeted, and there are no plans to kill the leader, said Gen. Carter Ham, the head of U.S. forces in Africa.
Ham said no Libyan aircraft have been observed flying since the airstrikes began Saturday.
However, a professor of Mideast studies at Johns Hopkins University said only so much can be achieved through aerial strikes.
"We have to understand the limits of what air power can do," Fouad Ajami told CNN's "AC360" Tuesday night.
"This is a recipe for a stalemate. He stays in his bunker. The people in Benghazi stay behind the line. Otherwise, this will go on for quite a long time."
Criticism and questions persist about the international campaign, with no clear answer on who will take over command and what the endgame or exit strategy will be.
U.S. President Barack Obama said the timetable for a transition of military leadership will be coming in days, not weeks.
NATO said Wednesday it will decide shortly what its role in the operation will be. A spokesman added the alliance is well prepared.
"This is the bread and butter of NATO," an official said.
Ajami said that unlike what some have suggested, the Arab world welcomes NATO involvement.
"They know that the calamity is unfolding in Libya, and they know that no help is going to come other than from the West and from the United States."
But Qatar is the only Arab country that has contributed planes to mission. The United States expects additional Arab support, a senior administration official said Tuesday.
The United Arab Emirates said Tuesday it will participate -- but only in providing humanitarian assistance.
Toward that end, the country has sent a ship and two planes with basic relief supplies, the country's news agency said.
Meanwhile, the French ambassador to the U.S. said the focus is to fulfill the U.N. mandate.
"We have a clear mandate of the U.N. Security Council that is about protection of the civilian population,"
Francois Delattre told CNN's Piers Morgan.
"That's one thing. Now if you ask me what is France's ultimate goal, I will answer quickly, very clearly: Gadhafi must go."