SNC Threatens to Boycott Geneva Talks as 300 Die in Week of Air Raids on Syria's Aleppo

Syrian warplanes have killed more than 300 people in an eight-day bombing campaign on Aleppo, with the opposition National Coalition saying it will not attend planned peaced talks if the bombing continues.

The vicious campaign has seen aircraft drop barrels of TNT on rebel-held neighborhoods -- a tactic widely condemned as unlawful -- flooding hospitals with victims, according to activists, medics and others.

The attacks come as President Bashar Assad's forces have advanced on several fronts recently while Western nations have been preoccupied with Syria's chemical disarmament and preparing for the January peace talks.

"From December 15 to 22, 301 people have been killed, including 87 children, 30 women and 30 rebels," said the Syrian Observatory for Human Rights, which relies on a network of activists and witnesses on the ground.

It later said 21 people had been killed Monday in attacks on the rebel-held Marjeh and Soukkari districts of Syria's second city, once its commercial capital.

Activists released what they said was footage of a school targeted in the village of Marea near Aleppo. Children can be seen running from the school and screaming as loud explosions rumble in the background.

Inside, men pull children from the rubble, their faces caked in dust and blood. It was not possible to verify the footage.

Assad's opponents say the bombing is aimed at demoralizing their supporters and turning them against the insurgents.

A security source told Agence France Presse the army had adopted the tactic because of a lack of ground forces, and argued the heavy civilian toll was because the rebels -- branded "terrorists" by the regime -- are based in residential areas.

Aleppo has been split between opposition and government forces since a massive rebel assault in July 2012.

Human Rights Watch has accused the government forces of using weapons and tactics that fail to distinguish between civilians and combatants, making such strikes "unlawful."

The main opposition National Coalition has called on Western states to impose a no-fly zone to halt the attacks.

"Until Assad's warplanes are stopped, the humanitarian disaster, regional instability and the rise of extremism will only continue to get worse," said Munzer Aqbiq, an adviser to the Coalition's president.

If bombing continues Coalition 'will not go to Geneva'

Later, Coalition Secretary General Badr Jamous went further and said that "if the bombing the Assad regime is carrying out and its attempt to annihilate the Syrian people continue, then the coalition will not go to Geneva."

The so-called Geneva 2 talks are aimed at getting agreement on a political transition to end the war, which has claimed an estimated 126,000 lives since March 2011 and displaced millions.

But the increasingly fractured opposition has said Assad must step down as part of any deal, which Damascus rejects.

And several powerful rebel groups have rejected the talks outright, raising concerns that even if an agreement is reached the opposition would be unable to enforce it on the ground.

The initiative is aimed at building on the momentum of a deal to eradicate Syria's vast chemical arsenal by mid-2014, which averted punitive U.S. strikes after an August gas attack near Damascus killed hundreds of people.

But analysts argue the regime has been emboldened by U.S. President Barack Obama's failure to act after Assad allegedly crossed his "red line" against using chemical weapons.

"There are no more red lines, there is a green light," Salman Shaikh, the director of the Brookings Doha Center, told AFP, saying there is an "element of vengeance" in the Aleppo bombings.

"Any credible use of force was taken off the table by Obama and the international community."

Meanwhile, Assad said Syria was being confronted with a major offensive by Islamist extremists.

"The country is facing a takfiri ideology," Assad said, using a term for Sunni Muslim extremists. "This is terrorism without limits, an international scourge that could strike anywhere and anytime."