By Maria Golovnina and Michael Georgy
TRIPOLI (Reuters) - Muammar Gaddafi's forces attacked two west Libyan towns, killing dozens while rebels were pinned down in the east and NATO tried to resolve a heated row over who should lead the Western air campaign.
With anti-Gaddafi rebels struggling to create a command structure than can capitalize on the air strikes against Libyan tanks and air defenses, Western nations have still to decide who will take over command once Washington pulls back.
The United States will cede control in days, President Barack Obama said, even as divisions in Europe fueled speculation that Washington would be forced to retain leadership of air patrols that will replace the initial bombardment.
"We anticipate this transition to take place in a matter of days and not in a matter of weeks," Obama, facing questions at home about the U.S. military getting bogged down in a third Muslim country, told a news conference on a visit to Chile.
In the first apparent air force casualty of the campaign, a U.S. F-15E crashed in Libya overnight and its two crew members were rescued, the U.S. military said. The crash was likely caused by mechanical failure and not hostile fire, it said.
In the latest fighting on Tuesday, Gaddafi's tanks shelled the rebel-held western city of Misrata and casualties included four children killed when their car was hit, residents said, adding the death toll for Monday had reached 40.
Residents painted a grim picture of the situation in Misrata which has been under siege by Gaddafi loyalists for weeks with doctors operating on people with bullet and shrapnel wounds in hospital corridors and tanks in the city center.
"The situation here is very bad. Tanks started shelling the town this morning," a resident, called Mohammed, told Reuters by telephone from outside the city's hospital, adding: "Snipers are taking part in the operation too. A civilian car was destroyed killing four children on board, the oldest is aged 13 years."
REBELS PINNED DOWN IN EAST
Al Jazeera news network said Gaddafi forces were trying to seize the western rebel-held town of Zintan near the Tunisian border in an attack using heavy weapons. Residents had already fled the town center to seek shelter in mountain caves.
Security analysts say it is unclear what will happen if the Libyan leader digs in, especially since Western powers have made clear they would be unwilling to see Libya partitioned between a rebel-held east and Gaddafi-controlled west.
Rebels in east Libya were positioned just outside Ajdabiyah on Tuesday, making no further advance on the strategic town despite a third night of Western air strikes on the north African oil-producing state.
At the frontline in the desert scrub about 5 km (3 miles) outside the town located at the gateway to the rebel-held east, rebels said air strikes were helping cripple Gaddafi's heavy armor. But there was no sign of a swift drive forward.
When asked why rebel units had not advanced toward their objective, which is the eventual taking of Tripoli, Ahmed al-Aroufi, a rebel fighter at the frontline, told Reuters: "Gaddafi has tanks and trucks with missiles."
Commenting on the air campaign to protect civilians in this uprising against Gaddafi's 41-year rule, Aroufi said:
"We don't depend on anyone but God, not France or America. We started this revolution without them through the sweat of our own brow, and that is how we will finish it."
Echoing rebel opposition to any intervention by foreign ground forces, he said: "We need the no-fly zone for them to strike the heavy armor. But if they bring land forces we will leave Gaddafi alone and they will be our new target."
Washington, wary of being drawn into another war after long campaigns in Iraq and Afghanistan, has ruled out specific action to overthrow Gaddafi, though France said on Monday it hoped the Libyan government would collapse from within.
Obama did not spell out which nation or organization would take charge of the campaign, but Britain and France took a lead role in pushing for air strikes in Libya which have already destroyed much of its air defenses.
NATO TALKS "EMOTIONAL"
British Prime Minister David Cameron said the intention was to transfer command to NATO, but France said Arab countries did not want the U.S.-led alliance in charge of the operation.
NATO officials resumed talks in Brussels on Tuesday after failing to reach agreement at heated talks on Monday.
Some allies were now questioning whether a no-fly zone was necessary, given the damage already done by air strikes to Gaddafi's military capabilities, a NATO diplomat said.
"Yesterday's meeting became a little bit emotional," the NATO envoy said, adding that France had argued that the coalition led by France, Britain and the United States should retain political control of the mission, with NATO providing operational support, including command-and-control capabilities.
"Others are saying NATO should have command or no role at all and that it doesn't make sense for NATO to play a subsidiary role," the diplomat said.
Underlining the differences in the anti-Gaddafi coalition, Italy's Foreign Minister Franco Frattini said if agreement was not reached on a NATO command, Italy would resume control of the seven airbases it has made available to allied air forces.
A NATO role would require political support from all the 28 states. Turkish Prime Minister Tayyip Erdogan, whose country is a NATO member, said on Tuesday that the United Nations should be the umbrella for a solely humanitarian operation in Libya.
In a speech in parliament Erdogan said: "Turkey will never ever be a side pointing weapons at the Libyan people."
Andrew Bacevich, a professor of international relations at Boston University, said it would be difficult to stand up a multinational command structure "on the fly."
"If that's what's being attempted then the hand-off may take longer than the Obama administration would like," he said.
Rifts are also growing in the world community over the U.N. resolution, with Russian Prime Minister Vladimir Putin comparing the mandate to a call for "medieval crusades." China and Brazil urged a ceasefire amid fears of civilian casualties.
Defense Secretary Robert Gates said on Tuesday on a trip to Moscow that some people in Russia seem to believe what he termed Gaddafi's "lies" about civilian casualties in Libya.
"We've been very careful about this and it's almost as though some people here are taking at face value Gaddafi's claims about the number of civilian casualties, which as far as I am concerned are just outright lies," Gates told reporters.
Libyan officials, who have said air strikes have killed dozens of civilians, have also said in the past the rebels are al Qaeda militants assisted by Western powers who are trying to steal Libya's oil.
Gates said he told his Russian counterpart Anatoly Serdyukov, who wants an immediate ceasefire to protect Libyan civilians, "that I thought the significant military fighting that has been going on should recede in the next few days."
Libyan television was showing archive footage of Gaddafi being greeted by cheering crowds waving his portrait. The images were set to stirring patriotic music. Gaddafi himself has not been since in public since the air strikes began at the weekend.
State television was also broadcasting old footage of military parades, including pictures of elite troops marching in formation wearing balaclavas and gas masks.
(Reporting by Mohammed Abbas and Angus MacSwan in Benghazi, Maria Golovnina and Michael Georgy in Tripoli, Hamid Ould Ahmed and Christian Lowe in Algiers, Tom Perry in Cairo; David Brunnstrom in Brussels, Phil Stewart in Moscow; Writing by Peter Millership; Editing by Giles Elgood)