Gaddafi attacks rebel towns, U.S. plane down, Posted by Meosha Eaton

* Residents in Misrata, Zintan say attacked

* NATO meets to discuss assault's command structure

* U.S. warplane crashes, crew rescued

* Analysts see stalemate as rebel army stalls

(Adds quotes from battlefield in east Libya, NATO meets)

By Maria Golovnina and Michael Georgy

TRIPOLI, March 22 (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 capitalise on the air strikes against Libyan tanks and air defences, 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 fuelled 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.

"The bombardment is focused on the town centre, and what is going on in Misrata is a massacre," Saadoun, a spokesman for the rebels in Misrata, told Al Jazeera. "The bombardment continues."

"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 centre to seek shelter in mountain caves.

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 armour. But there was no sign of a swift drive forward.

When asked why rebel units had not advanced towards 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 armour. 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 organisation 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 defences.

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 to deputies from his ruling AK Party 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 resolution, with Russian Prime Minister Vladimir Putin comparing the U.N. mandate a call for "medieval crusades". China and Brazil urged a ceasefire amid fears of civilian casualties.

ARCHIVE FOOTAGE OF GADDAFI

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.

Several sites in Tripoli had been subject to new attacks by what it called the "crusader enemy", state television said. "These attacks are not going to scare the Libyan people."

The United States and its allies have run into some criticism for the intensity of the firepower unleashed on Libya, including more than 110 Tomahawk missiles on Saturday. The next step is to patrol the skies to enforce the no-fly zone.

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. (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; Writing by Peter Millership; Editing by Giles Elgood)