Western warplanes hit Libyan tanks on a fifth night of airstrikes on Thursday but failed to stop Moammar Gadhafi's forces shelling rebel-held towns in the west or dislodge his armour in the east.
Air strikes destroyed government tanks on the outskirts of the rebel-held city of Misrata, but other tanks inside the city were not hit, a resident said.
Gadhafi's tanks had rolled back into Misrata under the cover of darkness and shelled the area near the town's main hospital, resuming their attack, residents and rebels said.
"The situation is very serious," a doctor in the western town said by telephone before the line was cut off.
Quarreling NATO
The strikes came as the United States turned up pressure on quarreling NATO allies to take command of the air war in Libya.
Western warplanes have so far failed to stop Gadhafi from shelling rebel-held towns or dislodge his armor from a strategic junction in the east.
Gadhafi's tanks were silenced during daylight hours on Wednesday returned to Misrata, 125 miles southeast of Tripoli, after night fell and began shelling the area near the main hospital, residents and rebels said.
Forces loyal to Gadhafi also seized control of Misrata's port on Wednesday, stranding thousands of Egyptian and sub-Saharan African migrant workers, who were seeking evacuation by sea, a resident told Reuters by telephone.
Several days of air strikes so far have failed to stop bombardments and shootings by snipers which, residents say, have killed dozens of people and wounded hundreds in Misrata, the last big insurgent stronghold in western Libya.
"Some tanks on the coastal road were bombed last night at around 6 p.m. (1 p.m. ET) but the tanks inside the city, in the center ... which were bombing the city, are still there and were not attacked," said the resident, called Abdelbasset.
"We have a humanitarian crisis at the port. There are more than 6,000 Egyptian workers, some with their families, plus some African workers, who are now in the port. They went there waiting for a ship to move them but nobody is coming.
Reports from the city could not be verified independently because Libyan authorities have prevented journalists from going there.
U.S. seeks handoff
NATO failed to agree on taking over military operations against Gadhafi's forces, chiefly because of Turkey's objections, diplomats said.
After ambassadors of the 28-nation alliance ended a third day of wrangling in Brussels without a deal, one senior NATO diplomat said: "No decision on anything."
U.S. officials said there is no absolute deadline for the United States to hand over front-line control of the military operation to other countries, or for an end to all U.S. participation. The Obama administration is eager to hand off the lead role in a conflict that some of President Barack Obama's closest advisers resisted and that is raising complaints in Congress.
Defense Secretary Robert Gates, an early skeptic of U.S. military intervention in Libya, said Obama made clear from the start of the international air campaign last Saturday that the U.S. military would run it only for about one week. The assault began with a barrage of U.S. cruise missiles, fired by ships and submarines in the Mediterranean, and American Stealth bomber flights, the first war initiated by a president who inherited two others.
In an exchange with reporters traveling with him in Cairo on Wednesday, Gates was asked whether that meant the U.S. had set a hard deadline of this Saturday for turning over command of the air operations.
"I don't want to be pinned down that closely," he replied. "But what we've been saying is that we would expect this transition to the coalition, to a different command and control arrangement, to take place within a few days, and I would still stand by that."
The U.S. and its partners are struggling to overcome a key dilemma of their mission: how to halt Gadhafi's ground forces, which are now attacking urban areas, without endangering the very civilians the allies are supposed to be protecting.
Turkey, the sole Muslim member of NATO, said it did not want NATO to take responsibility for offensive operations that could cause civilian casualties or be in charge of enforcing a U.N.-mandated no-fly zone while coalition aircraft were simultaneously bombing Libyan forces.
Gadhafi's regime has alleged that dozens of civilians have been killed in the international bombardment, but the Pentagon and coalition officials say no claims of civilian casualties have been independently verified.
"It would be impossible for us to share responsibility in an operation that some authorities have described as a 'crusade'," Turkish Foreign Minister Ahmet Davutoglu told reporters in Ankara. Russian Prime Minister Vladimir Putin has used that term, as has Gadhafi.
Envoys would meet again Thursday to try and nail down rules determining circumstances under which the military alliance can use force, a NATO diplomat said, speaking on condition of anonymity, since he was not authorized to speak about internal deliberations to reporters.
The Pentagon said that over the past day, the coalition flew 175 air missions, including noncombat flights. Of that total, 113 flights, or about 65 percent, were flown by U.S. planes, and 62 by other nations' aircraft. Three days earlier, the U.S. share was 87 percent, the Pentagon said.
French Defense Minister Gerard Longuet said France had destroyed some 10 Libyan armored vehicles over three days.
The U.N. Security Council resolution he said, "stipulates that the coalition has all means available to protect the civilians. What's threatening the population today is the tanks and artillery," he said in an interview with Le Figaro published on Thursday.
Rear Adm. Gerard Hueber, a top U.S. officer in the campaign in Libya, said international forces were attacking government troops that have been storming population centers.
From Ajdabiya in the east to Misrata in the west, the coalition's targets included mechanized forces, mobile surface-to-air missile sites and lines of communications that supply "their beans and their bullets," Hueber told Pentagon reporters by phone from the U.S. command ship in the Mediterranean sea.
The Libyan government denies its army is conducting any offensive operations and says troops are only defending themselves.
Gadhafi's compound in Ajdabiya was subject to air strikes, a day after he addressed supporters there, Arabiya TV reported Wednesday.
Libyan state television said Western planes had struck in Tripoli and in Jafar, southwest of the capital. "Military and civilian targets were attacked by colonialist crusaders," the television said.
Gadhafi forces pushed back during day
A doctor in Misrata said Gadhafi's tanks fled after the airstrikes on Wednesday, giving a much-needed reprieve to the besieged coastal city, which is inaccessible to human rights monitors or journalists.
"Today, for the first time in a week, the bakeries opened their doors," the doctor said, speaking on condition of anonymity for fear of reprisals if Gadhafi's forces take Libya's third-largest city, 125 miles southeast of Tripoli.
He and rebel leaders said pro-Gadhafi snipers continued to fire on civilians from rooftops on Wednesday.
In Zintan, a resident said Gadhafi's forces were shelling from the foot of a nearby mountain, but rebels forced their retreat from all but one side of the city. After five days of fighting, Ali al-Azhari said, rebel fighters captured or destroyed several tanks, and seized trucks loaded with 1,200 Grad missiles and fuel tanks. They captured five Gadhafi troops.
Al-Azhari, who spoke to The Associated Press by phone from the city, said one officer told rebels he was ordered "to turn Zintan into a desert to be smashed and flattened." Resentment against Gadhafi runs high in Zintan, a city of 100,000 about 75 miles south of Tripoli, because it was the hometown of many of the detained army officers who took part in a failed coup in 1993.
NATO warships patrolNATO warships began patrolling off Libya's coast Wednesday to enforce the arms embargo. It had agreed to do so on Tuesday.
Canada's Brig. Gen. Pierre St. Amand said naval operation Unified Protector "is now under way" with six vessels involved during the first day of patrols. NATO had already received offers for up to 16 ships to patrol the Mediterranean off Libya, he said.
Turkey is an integral part of the naval blockade, having offered four frigates and one submarine, St. Amand said. Other nations offering vessels are the United States, Romania, Italy, Canada, Spain, Britain and Greece.
Also on Wednesday, an American military official said the U.S. bombed the wreckage of the F-15 fighter jet that went down in Libya Monday night due to a mechanical failure.
The official, speaking on condition of anonymity, said that the wreckage was bombed overnight "to prevent materials from getting into the wrong hands."
Prolonged conflict?Gen. David Petraeus, the commander of U.S. and NATO forces in Afghanistan, said on Wednesday he was not concerned that the Libya no-fly zone would divert military resources from the war in Afghanistan.
"The short answer is 'no,' " Petraeus said.
"There was an examination of whether certain intelligence, surveillance, and reconnaissance assets of an actually quite limited nature might be needed to help out with the operation in Libya, but in the end there have been no assets taken from the effort in Afghanistan and I don't foresee that happening at this point in time," Petraeus said, speaking at the Royal United Services Institute defense think-tank in London.
Pro-Gadhafi troops who have besieged Ajdabiya — a city of 140,000 that is the gateway to the east — attacked a few hundred rebels gathered on the outskirts Wednesday. The rebels fired back with Katyusha rockets but have found themselves outgunned by the Libyan government's force.
Plumes of smoke rose over the skyline of the city, which is 95 miles south of the de-facto rebel capital of Benghazi.
"The weapons they have are heavy weapons and what we have are light weapons," said Fawzi Hamid, a 33-year-old who joined the Libyan military when he was younger but is now on the rebels' side. "The Gadhafi forces are more powerful than us so we are depending on airstrikes."
People fleeing the violence said the rebels had control of the city center while Gadhafi's forces were holding the outskirts.
"The pro-Gadhafi forces are just shooting everywhere. There is no electricity, the center of the city has been totally destroyed, even the hospital has been hit," 28-year-old Hafez Boughara said as he drove a white van filled with women and children on a desert road to avoid the main highway.