Raids Shake Syria's Aleppo as U.N. Holds Crisis Talks

Intense air raids shook Syria's Aleppo and killed a team of medics as the U.N. Security Council held crisis talks Wednesday on reviving a failed ceasefire.

The mood at the U.N. meeting in New York was likely to be tense after the United States said it held Russia responsible for a deadly air strike on an aid convoy.

U.S. Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov were both to address the council, ahead of more talks on salvaging the truce -- which collapsed on Monday -- later this week.

U.N. Secretary General Ban Ki-moon told the meeting it was a "make or break moment" for Syria, urging world powers to use their influence to help re-start political talks so Syrians can "negotiate a way out of the hell in which they are trapped."

Russia and the United States co-sponsored the ceasefire plan, with Kerry warning it could be the "last chance" to try to end Syria's civil war, which has killed more than 300,000 people in five years.

But peace efforts have been hindered by attacks on aid workers, most recently a deadly raid on a medical team near Aleppo late Tuesday. 

The Union of Syrian Medical Relief Organizations (UOSSM) said the strike hit two of its ambulances in Khan Tuman, a village south of Aleppo city, as workers evacuated victims from a previous strike.

It said two nurses and two ambulance drivers were killed and another nurse was critically wounded. 

The Syrian Observatory for Human Rights, a monitoring group, said the initial raid killed nine medical staff affiliated with the Army of Conquest rebel alliance.

On Wednesday, heavy bombardment pummeled Aleppo city and the wider province, key battlegrounds in Syria's conflict. 

The Britain-based Observatory said dozens of raids hit the city's east overnight, as regime troops advanced on rebels in Aleppo's southwestern outskirts.

- Raids on northwest Syria -

It was a sleepless night for many Aleppo residents, AFP's correspondent in the city said on Wednesday, with bombardment continuing until rain broke out over the city at dawn.

Civil defense workers in the Qadi Askar neighborhood weaved through rubble in search of wounded residents in a row of buildings hit by air strikes Wednesday. 

In the rebel-held neighborhood of Sukkari, Abu Ahmad cleared rubble and shattered glass from his doorstep after bombardment leveled the six-story building next door, killing his neighbors.

He had tea with the two brothers who lived in the building late the previous night. 

"Just an hour after I left, a missile destroyed their whole building and they both died under the rubble," Abu Ahmad said.  

Syrian state media reported that the city's government-held west had come under rebel shelling, which killed two people.

Seven civilians, including three children, were also killed in unidentified air raids on the northwestern town of Khan Sheikhun Wednesday, according to the Observatory.

Bombardment has escalated across the country since Monday evening, when Syria's military declared an end to the week-long truce that had brought relative calm to major fronts. 

Hours after the announcement, an air strike hit an aid convoy near Aleppo, killing 20 civilians and destroying 18 trucks, the Red Cross said. 

Monday's strike sparked international outrage and prompted an exasperated U.N. to suspend all humanitarian convoys across Syria.

"There only could have been two entities responsible, either the Syrian regime or the Russian government," President Barack Obama's national security spokesman Ben Rhodes said.

"In any event, we hold the Russian government responsible for air strikes in this space."

- 'Hasty accusations' -

Two Russian SU-24 ground attack jets were operating in the area where the aid convoy was struck, another U.S. official told AFP. 

"The best evaluation we have is that the Russians carried out the strike," he added, speaking on condition of anonymity.

The Russian foreign ministry said the "unsubstantiated, hasty accusations" seemed designed to "distract attention from the strange 'error' of coalition pilots."

This was a reference to Saturday's bombardment and killing of dozens of Syrian troops by the U.S.-led coalition fighting the Islamic State group, an attack which Washington said was a mistake.

Despite the tensions, Kerry insisted that efforts to salvage the truce were "not dead", after a short meeting of the 23-nation International Syria Support Group (ISSG) in New York, where world leaders have gathered for the U.N. General Assembly. 

Kerry's spokesman John Kirby said it had been agreed that "despite continued violence" diplomats would use the agreement between the United States and Russia as a basis for more talks.

The deal foresaw an end to fighting between President Bashar Assad's forces and non-jihadist rebels, aid deliveries to besieged areas and, if the ceasefire held for seven days, cooperation between Moscow and Washington in battling IS and other extremist groups.