TRIPOLI (Reuters) - Libyan leader Muammar Gaddafi's forces resumed their attack on the rebel-held town of Misrata on Wednesday, moving back onto the offensive just hours after Western strikes silenced their guns.
While initial Western airstrikes hit Libyan air defences and an armoured column in the east, Gaddafi's tanks kept up their shelling of Misrata in the west, killing dozens there this week.
Residents said a "massacre" was taking place with tank and artillery fire destroying buildings and snipers picking off people indiscriminately. Doctors were operating in hospital corridors and having to turn some of the wounded away.
The U.S. military said it had successfully established a no-fly zone over Libya's coastal areas and had moved on to attack Gaddafi's tanks. Western planes launched a series of air strikes near Misrata and stopped the tank and artillery fire.
But as darkness cloaked the city, Libya's third largest, Gaddafi's tanks began to roll once again.
"Government tanks are closing in on Misrata hospital and shelling the area," said the doctor who was briefly reached by phone before the line was cut off.
A rebel spokesman said 16 people had been killed in Misrata and another six in attacks on Zintan, a rebel-held town in west Libya. It was impossible to independently verify the reports.
During the day, while the tanks and artillery fell silent, the Western air strikes did not stop the snipers in Misrata.
"The snipers are ... shooting at the hospital and its two entrances are under heavy attack. No one can get in or out," Saadoun, a Misrata resident, told Reuters by telephone.
While the fighting raged, NATO again failed to agree after a third day of negotiations to take over command of the military operations from the United States, chiefly because of objections from Turkey, diplomats said.
Gaddafi called Western powers carrying out air strikes "a bunch of fascists who will end up in the dustbin of history."
"We will not surrender," he told supporters forming a human shield to protect him at his Tripoli home which came under U.S. attack in 1986 and once again in the current round of air raids.
Eight explosions were heard in the east of Tripoli on Wednesday evening and smoke was seen rising into the night sky, local residents told Reuters.
"We heard four explosions, then after five minutes we heard four more," said a resident in the eastern Tajoura district. "We saw smoke and fire afterwards. "Several distant thuds were heard by Reuters reporters in central Tripoli.
Libyan state television said Western planes had hit military and civilian targets in Tripoli without giving further details.
Libyan government officials have accused Western powers of killing dozens of civilians, but have not shown reporters in the capital any evidence of such deaths. U.S. military officials denied any civilians had been killed in airstrikes.
"There have been no reports of civilian casualties. Our mission here is to protect the civilian populace and we choose our targets and plan our actions with that as a top priority," Rear Admiral Gerard Hueber told reporters by phone from the command ship USS Mount Whitney in the Mediterranean.
The allies had flown 175 sorties in the last 24 hours, with the U.S. flying 113 of those, he said.
Hueber said there was no evidence of Gaddafi's forces pulling back from Misrata and Ajdabiya and widespread reports of Gaddafi's forces engaged in fighting in those and other cities, "putting innocent civilians in grave danger."
"As a result we are pressurizing Gaddafi's forces that are attacking those civilian populations," he said.
The Libyan government denies its army is conducting any offensive operations and says troops are only defending themselves when they come under attack. But a resident in Zintan said Gaddafi forces were bringing in reinforcements.
"Gaddafi's brigades started bombardment from the northern area half an hour ago. The bombardment is taking place now. The town is completely surrounded. The situation is very bad," the resident, Abdulrahman, told Reuters by telephone from the town.
"They are getting reinforcements. Troops backed with tanks and vehicles are coming. We appeal to the allied forces to come and protect civilians," he said.
But the United States, with its forces already tied up in Iraq and Afghanistan, has said it wants to take a back seat.
The White House said it wants to give up its lead role in Libya in a "matter of days" and wants the alliance to play an important role in the command of the operation, though the exact structure of its role was still under discussion.
"I think this is going to be a matter of days in which you see a movement towards the transition with regard to command and control," a top aide to President Barack Obama told reporters.
Washington, London and Paris agreed on Tuesday that the alliance should play a key operational role, but the assent of all 28 NATO states is needed. Objections from Muslim NATO member Turkey have held up agreement on the alliance's role for three days and a fourth day of talks is due on Thursday.
Turkey 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.
France wants an ad hoc steering group of coalition members, including the Arab League, to exercise political control. All nations are welcome to join, a French presidential source said.
"We need to have a place where all those who want to commit to help Libyans build a future can meet and discuss a political framework," he said. "It's about accompanying the military process with a political one."
The group is due to meet in London next Tuesday.
"We've launched the idea of a contact group and apparently it's a big success," the French source said.
REBELS FIGHT TO BREAK IMPASSE
In the east of this oil-producing north African desert state, disorganised and badly equipped rebels fighting to end Gaddafi's 41-year rule have failed to capitalise on foreign air strikes and have been pinned down outside Ajdabiyah, 150 km (90 miles) west of Benghazi.
Rebels were clashing with the army inside Ajdabiyah, rebel fighters said on Wednesday, and residents were fleeing.
Fighters said some groups had made covert forays into the town through the desert but that tanks at the town entrance had kept their main force at bay.
"We went into Ajdabiyah yesterday (Tuesday) at 2 p.m. It's not Ajdabiyah any more," said rebel fighter Faraj Ali, in his machinegun-mounted truck. "It's dead, destroyed, a ghost town."
A family leaving Ajdabiyah said a fraction of the residents remained. "I saw bodies in the streets, and buried and washed some myself as they're rotting in the morgue. There's not been electricity for a week," said one man, declining to be named.
(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, Andrew Quinn in Washington, Catherine Bremer, Emmanuel Jarry and Yves Clarisse in Paris; writing by Peter Millership and Jon Hemming; editing by Jon Boyle).