Near Ajdabiya, Libya — Libyan forces pounded rebel cities with tank fire forcing civilians to flee as a top British officer said Muammer Qadhafi's air force had been almost obliterated.
As an armada of NATO warships patrolled Libya's coast to enforce an arms embargo against Qadhafi, fresh efforts to hand the alliance command of the military operations collapsed after days of sometimes acrimonious debate.
A NATO diplomat said the 28-nation alliance would try again on Thursday to reach a decision on whether NATO should take charge of the operation launched on Saturday by Britain, France and the United States.
But nations were already hailing the success of the air strikes, with British Air Vice Marshal Greg Bagwell saying Libya's air force has been almost totally obliterated and "no longer exists as a fighting force."
US officials are also openly speculating whether the continued pressure will force Qadhafi out of power after four decades in control.
At the end of a day of bitter fighting in key rebel strongholds, pro-Qadhafi forces pounded a hospital in the western city of Misrata, a rebel spokesman said.
Witnesses also reported a huge blast at a military base in the Tajura residential neighbourhood some 32km (20 miles) east of the capital, while anti-aircraft fire was heard as warplanes thundered over Tripoli.
The official JANA news agency said coalition raids on Tajura killed "a large number" of civilians.
Tajura was struck three times, the agency said, adding the third raid "targeted rescuers who were trying to remove the dead and wounded from the rubble and the destruction caused by the first two raids."
A huge blast was also heard late Wednesday at a military base in the Tajura region, witnesses told AFP, adding flames were seen shooting from the base.
Tajura is home to the most important Libyan military bases and was struck by allied forces on the first day of operations on Saturday, launched against Libya to impose a UN no-fly zone on the country.
Although the endgame in Libya remains unclear, US Defence Secretary Robert Gates said during a visit to Egypt that mounting pressure on Qadhafi's regime could encourage his associates or even members of his family to turn on him.
"I think there are any number of possible outcomes here and no one is in a position to predict them, whether there are further major defections within his own ruling circle, whether there are divisions within his family," he said.
US President Barack Obama has insisted Qadhafi must step down, and US officials hinted that members of Qadhafi's inner circle were reaching out to find a way out of the crisis.
The US military also said Qadhafi's ground troops threatening rebel-held cities were now being targeted by coalition air strikes.
"We are putting pressure on Qadhafi's ground forces that are threatening cities," said Rear Admiral Gerard Hueber, US chief of staff for the Libya mission.
French Defence Minister Gerard Longuet said "the air exclusion zone has become a reality."
"The French side has taken out a dozen armoured vehicles in three days," he told Le Figaro newspaper in an interview to be published on Thursday. "This is decisive as we have practically not seen any tank concentrations since the strikes."
Canadian warplanes bombed their first target in Libya overnight, destroying a munitions depot in the rebel-held city of Misrata, Libya's third city 214km(132 miles) east of Tripoli, military officials said.
White House spokesman Ben Rhodes confirmed that after forcing Kadhafi's forces to pull back from eastern Benghazi "we're similarly focused on trying to protect the people of Misrata as well."
Late on Wednesday, Qadhafi forces using tanks pounded the only hospital in Misrata, which has been besieged by regime loyalists for weeks, a witness and a rebel spokesman said.
"The situation here is very bad and very serious. The tanks are shelling the hospital and houses," said the spokesman. On Tuesday 17 people were killed by snipers and shelling in Misrata, a doctor said.
Residents fleeing Ajdabiya, a strategic eastern town south of rebel capital Benghazi, described shelling, gunfire and burning houses, while an AFP reporter said a pall of smoke hung over the town and intermittent explosions were heard.
A man driving a car with his panicked family on the coast road north of the city told AFP they were too scared to stay. "We left because of the fighting. We were very scared; we cannot stay."
Hamed al-Qabaili, also fleeing Ajdabiya, said Qadhafi forces "are firing Grad missiles at the houses," while fellow passenger Muftah al-Sheikh said "very few people" stayed behind. "There is no electricity and no gas."
UN chief Ban Ki-moon again urged all sides in Libya to cease fire as the Security Council prepared to meet on Thursday, a week after clearing the way for action against Qadhafi.
"All those who violate international humanitarian and human rights law will be held fully accountable," Ban's spokesman Martin Nesirky said, mentioning attacks on Misrata and Zintan, also in the west.
Coalition forces are acting under UN Security Council Resolution 1973 authorising "all necessary means" to protect civilians fighting to topple Qadhafi, including enforcing a no-fly zone.
In Berlin, coalition spokeswoman Beverly Mock reported 97 sorties across Libya in the 24 hours ending at 12 GMT on Wednesday, with air strikes targeting tanks, anti-aircraft batteries and "command centers."
Since the start of the operation on Saturday, the US and British navies had fired 162 Tomahawk cruise missiles — 112 on Saturday alone.
In Paris, an envoy from the rebels' transitional council said their objective was a "democratic and secular" regime.
Mansour Saif al-Nasr also predicted that Qadhafi would fall quickly, paving the way for society to be rebuilt. "The Libyan people are a moderate people, and the state will not be led by clerics."
The interim council has 31 members, but the identities of only eight have been revealed since most still live in zones held by Kadhafi loyalists.
Six nations agreed to contribute up to 16 vessels to prevent Qadhafi from bringing in weapons via the Mediterranean, with Turkey offering five warships and a submarine despite its reservations about the military action.
But the Western alliance is still bickering over who should take overall command.
France has insisted on a committee of coalition countries so as not to alienate Arab states, while Italy has demanded a single command under NATO.
Meanwhile, US Secretary of State Hillary Clinton said Washington expects "more announcements" of Arab participation in the campaign in the coming days.
Qatar has deployed Mirage fighters, the only Arab state so far to commit military assets to the coalition. British Prime Minister David Cameron said Kuwait and Jordan would provide a logistical contribution.
Oil prices rose for the third straight day on Wednesday amid more signs of rising demand and continued turmoil in crude exporter Libya.