Gaddafi calls on allies to halt air strikes as his forces bomb Misurata (UPDATES) (VIDEO)

Coalition planes reportedly circled overhead as Muammar Gaddafi's forces pounded a key city near the Libyan capital on Tuesday, whil members of the "contact group" of nations mounting air strikes in Libya met in London to debate the country's future

CNN reported that Libyan tanks fired mortar shells and heavy artillery on Misurata, 100 miles east of Tripoli, in an effort to retake the city, causing carnage "beyond imagination," forcing resident to flee and leaving the way open for Gaddafi's troops to loot homes.  

Further east, Libya's rebel army reportedly struggled to hold gains made in Sirt, Gaddafi's home town, on Tuesday.

And in a dramatic development, there was speculation that Gaddafi's foreign minister, Mousa Kousa, might have defected during a visit to Tunisia, the Guardian reported.

The one-day meeting, involving Secretary of State Hillary Clinton, United Nations Secretary-General Ban Ki-moon, representatives from NATO, the Arab League, and the African Union, and around 40 foreign ministers were in talks in London, comes after President Barack Obama sought to defend the U.S. role in Libyan military action.

In a speech, Obama said air strikes in Libya prevented massive slaughter while cautioning that inaction would carry “a far greater price for America.”

“For those who doubted our capacity to carry out this operation, I want to be clear: the United States of America has done what we said we would do,” said Obama in his 25-minute address delivered at the National Defense University in Washington.

It has been designed to take stock of progress on the ground and discuss how best to proceed and comes hours after US President Barack Obama justified the reasons behind military action.

Gaddafi, meanwhile, likened the NATO-led air strikes to military campaigns launched by Adolf Hitler during World War II and urged international powers to end their "barbaric offensive" against his country.

In a letter letter sent to the European Parliament, the U.S. Congress and "the Europeans," Gaddafi accused the international community of carrying out genocide against the Libyans. “What is happening now is providing a cover for Al Qaeda through air strikes and missiles to enable Al Qaeda to control North Africa and turn it into a new Afghanistan,” he reportedly wrote.

Contrary to belief, Libya had made every effort to help solve global problems, he reportedly wrote — by abandoning its weapons of mass destruction, helping the international effort to fight "extremist terrorism," controlling illegal immigration to Europe and playing a positive role in Africa, he wrote, according to the Guardian.

"There were no demonstrations in Libya or protests like in Tunisia and Egypt," he reportedly wrote. "No one opened fire on demonstrators. No more than 150 people were killed and most of those were soldiers and policemen who were defending themselves."

In Libya, meanwhile, battles have been under way in Misrata, Libya's third-biggest city, for weeks. CNN reported that Gaddafi's troops were killing and wounding civilians and evicting thousands of people from their homes, a day after his regime tried to convince journalists that it was in control of Misurata by taking them on a trip through part of the city.

Libyan state TV featured a banner Tuesday that read: "Civilian and military locations in Misurata, Tripoli, Zaltin, Mazda and al-Watiya are being bombed by the crusaders and colonial enemies."

CNN quoted an opposition councilman as saying: "The carnage and the destruction and the human suffering from both the evictions and… terrorizing the city — it's beyond imagination."  

Off the coast of Misurata, meanwhile, U.S. military planes destroyed one of three Libyan ships said to be firing indiscriminately at merchant vessels in the port, military officials said in a statement Tuesday, CNN reported. 

And government tanks and rockets drove back rebels mounting an assault on Sirt, Gaddafi's home town, on Tuesday, demonstrating the superior firepower and organization of Gaddafi’s forces, despite a sustained campaign of air strikes by the U.S. and its allies.

The U.N.-mandated no-fly zone has brought the rebels back from the brink of defeat by government forces and helped them retake two key oil towns — Brega and Ajdabiya — along the road to Tripoli from the rebel stronghold of Benghazi.

Rebels made it to Nawfaliyah, about 60 miles from Sirt on Monday, according to the Associated Press, but had apparently been driven back by a Libyan bombardment to Bin Jawwad, a few dozen miles to the east.

“Gaddafi's forces are firing from Wadi al-Ahmar, including grad rockets, artillery and mortars,” the AP quoted a rebel fighter as saying, referring to a strategic valley outside Sirt. “It’s very intense.”

Sirt, a Gaddafi stronghold dominated by members of the Libyan leader’s tribe, is about halfway between the rebel-held east of the country and Gaddafi-controlled west. Capturing the city of 100,000 could energize the opposition and give rebel fighters momentum as they try to capture Tripoli.

Soldiers from a brigade commanded by Gaddafi's son, al-Saadi al-Gaddafi, reportedly streamed to positions on the city's outskirts to defend it on Monday.

And according to the AP, "Tuesday’s shelling and the undisciplined volunteers’ disorganized flight in pickup trucks showed that the rebels’ fundamental inability to counter Gaddafi’s heavy weapons without extensive outside help."

GlobalPost's James Foley, reporting from Libya on Tuesday, writes that the rebel army consists mostly of civilian volunteers who "don’t possess the military training or the command structure necessary to carry out a full-force attack on cities considered bastions of support for the Libyan leader."

In a sign of emerging ties between the opposition and the international community, meanwhile, the U.S. has dispatched an envoy — American diplomat Chris Stevens — to meet with the Libyan rebels in Benghazi, according to the AP — a pre-emptive move to establish ties with the group hoping to oust Gaddafi.

The move did not constitute formal recognition of the opposition, the AP quoted an unnamed official as saying.

And on Monday, Qatar joined France in recognizing the rebel-led Libyan National Council as the sole legitimate representative of the Libyan people. Qatar also said it would buy their oil and sell it on the broader market.

"The council, which includes representatives of various Libyan regions, has already begun representing the whole of Libya and has been recognized by the Libyan people," the Qatar news agency quoted a source in the Qatari Foreign Ministry as saying.

The meeting in London on Tuesday takes place amid increased criticism of the strikes on Gaddafi's troops and, according to Sky News, "an emerging fear in the Arab world that efforts at securing a no-fly zone and protecting the public are a precursor to regime change."

In a communique released ahead of the conference, British Prime Minister David Cameron and French President Nicolas Sarkozy reportedly said: "We emphasize that we do not envisage any military occupation of Libya, which would be contrary to the terms of the Resolution. We reaffirm our strong commitment to the sovereignty, independence, territorial integrity and national unity of Libya.

"Military action is not an objective as such. A lasting solution can only be a political one that belongs to the Libyan people. That is why the political process that will begin… in London is so important.

"There are clear contradictions here. We consider that intervention by the coalition in what is essentially an internal civil war is not sanctioned by the U.N. Security Council resolution.

"The London conference will bring the international community together to support Libya's transition from violent dictatorship and to help create the conditions where the people of Libya can choose their own future."

— Freya Petersen