Forces loyal to Muammar Gaddafi attacked a town near Tripoli on Tuesday after a third night of air raids on the capital, but the Western campaign faced questions over the future of its command structure.   

With anti-Gaddafi rebels struggling to capitalise on the air campaign and to set up a coherent command structure, Western nations have still to decide who will run the operation once Washington pulls back.   

The United States will cede control of the air assault in days, President Barack Obama said, even as divisions in Europe fuelled speculation that Washington would be forced to continue leadership of air patrols to 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 US military getting bogged down in a third Muslim country, told a news conference on a visit to Chile.

Libyan state television said several sites had come under attack in Tripoli on Monday. There was no immediate confirmation of new strikes by Western powers in the campaign to enforce a no-fly zone and protect civilians after an uprising against Gaddafi's 41-year rule.

In the latest fighting on Tuesday, Al Jazeera reported that Gaddafi forces were trying to seize the western town of Zintan in an attack using heavy weapons. Residents had already fled the centre of the town to seek shelter in mountain caves.    

Rebels, who were driven back towards their eastern Benghazi stronghold before the air attacks halted an advance by Gaddafi forces, have done nothing to resume their planned advance on Tripoli -- raising fears the war could grind to a stalemate.

But 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.        

British Prime Minister David Cameron said the intention was to transfer command to Nato, but France said Arab countries did not want the US-led alliance in charge of the operation in the oil-producing north African desert state.   

Nato officials were due to resume talks in Brussels on Tuesday after failing to reach an agreement on Monday.   

Italy's Foreign Minister Franco Frattini said if agreement was not reached for Nato control of the no-fly zone over Libya, Italy would resume its own separate command structure.

A Nato role would require political support from all the 28 Nato states, and on Monday Turkish Prime Minister Tayyip Erdogan said Turkey wanted several conditions met for a Nato role.   

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 Libya,  with Russian Prime Minister Vladimir Putin comparing the UN resolution to a call for "medieval crusades". China and Brazil were urging a ceasefire amid fears of civilian casualties.

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

Anti-aircraft gunfire rang out throughout the night and pro-Gaddafi slogans echoed around the city centre. Cars sped through Tripoli streets honking wildly.   

Al Jazeera television said radar installations at two air defence bases in eastern Libya had been hit.  A Libyan government spokesman also said that foreign attacks had killed many people by bombing ports and Sirte airport.

"You saw that place (Sirte airport)," Mussa Ibrahim told a news conference. "It's a civilian airport. It was bombarded and many people were killed. Harbours were also bombarded."    

Meanwhile, residents in two besieged rebel-held cities in western Libya, Misrata and Zintan, said they had been attacked by Gaddafi forces. Security analysts have said they believe government troops will try to force their way into civilian areas to escape attack from the air. - Reuters