Syrian government forces shelled parts of the restive northern city of Homs Saturday, causing numerous casualties, say witnesses. Dozens of people were killed or wounded Friday, after security forces opened fire on demonstrators in towns and cities across the country. Arab League foreign ministers are also demanding that the government stop firing on unarmed civilians.

Syrian troops loyal to President Bashar al Assad used tanks and field artillery to bomb the Bab Amr neighborhood of Homs Saturday, destroying and damaging peoples houses, according to videos broadcast on Arab sat channels.

Witnesses say that there have been numerous casualties during two days of violent and indiscriminate bombardment. One man told Al Jazeera TV that many victims are still holed up in their damaged homes, because it was "impossible to evacuate the wounded."

Al Arabiya TV reported that 90 soldiers defected from the Syrian Army in the Bab Amr district Thursday, causing pro-Assad troops to attack.  A Syrian opposition leader also told the TV that the regime is "worried that rebel soldiers turn Homs into their capital, as Libyan rebels did with Benghazi."

Fouad Ajami, a senior fellow at the Hoover Institute in California, points out that Homs, and the northern city of Hama, have always had bad relations with the Assad regime, and are taking the lead in the more than 7 month old popular uprising:

"Homs has emerged as the capital of the rebellion and I think for obvious reasons. Homs and Hama have always been, their traffic with the regime, their relation with the regime is not very good. And what's interesting, the demography of Hama is more Sunni. The demography of Homs is more mixed. So the demography of Homs is explosive. Neighborhoods are close, but they're also defined neighborhoods, there are Alawi neighborhoods, Christian neighborhoods, Sunni neighborhoods. So, this is how street warfare and urban warfare develops," he said.

Syrian government TV showed a man who belongs to President Bashar al Assad's Alawite sect, claiming that "Sunni terrorists" killed part of his family. He added that the alleged "terrorists" were being armed and given money by agents in Lebanon.

Over 40 people were reportedly killed during popular protests in several dozen Syrian towns and cities Friday, when snipers and government security forces fired on them. It is not clear if the casualty figures also include victims of violent clashes between army defectors and government troops in Homs, Hama and the southern city of Daraa.

Fouad Ajami argues that the Assad government is trying desperately to crush the rebellion, because it is in a bad situation financially, while the protesters are tired but resilient. "The regime is in a hurry to put down the rebellion, because it's running out of money. The people are in a hurry to distract the regime because they've suffered enough and they're afraid fatigue will set in. So, the terms of engagement are very clear: the regime has to win in a hurry," he said. ??Meanwhile, an Arab League committee on Syria has sent an urgent message to the Assad government, demanding that it "stop killing Syrian civilians."

The Qatari FM heads the committee and is due to meet with Syrian officials in Doha Sunday to try and start a dialogue with the opposition. Several opposition leaders are calling the meeting "a waste of time."

Fouad Ajami says that many opposition protesters cannot now abandon the fight, because they have been identified by pro-regime forces and will be killed if a ceasefire is called.

"It's an irresistable force clashing with an immovable object. The irresistable force are these protests, the people-it's too late for them to give up on the insurgency, the protests, the rebellion, and the regime is not yet done-so that's a classic ingredient for a civil war, because for the protesters, many of them can never go back to their homes. It's such a controlled setting, that the regime and its vigilantes, they know the names of the protesters. So for the protesters, it's too late, they must win or die. Now, for the rulers, they must stay in power and maybe also die, ergo Gadhafi. There's no quick resolution in sight," he said.

Ajami says that it's still too soon to decide who is going to win the conflict, but he points out that "gravity is working against the regime."