A spike in regime air attacks and fighting has sent the death toll in Syria's war soaring, as mediator Lakhdar Brahimi struggles to prevent peace talks in Geneva collapsing.
On Thursday, the Syrian Observatory for Human Rights reported at least 51 people killed a day earlier in Aleppo alone, mostly civilians in air raids targeting opposition-controlled areas, as dozens more were killed in the south.
In ravaged Homs, where a humanitarian operation began last Friday, governor Talal al-Barazi said the authorities would focus on screening and clearing scores of men detained after being evacuated from besieged rebel-held areas.
The Observatory has reported an average of 236 people killed daily since the Geneva II process began on January 22, bringing regime and opposition representatives to the negotiating table but producing no concrete result.
In Switzerland, the opposition National Coalition laid out a transition plan, including evicting foreign fighters and a process towards elections.
But the government refused to discuss it, saying the first item on the agenda was the battle against what it calls rebel "terrorism".
Key regime ally Russia, meanwhile, said a draft UN Security Council resolution it has presented on Syria does not include the threat of sanctions on Damascus.
Foreign Minister Sergei Lavrov said the original draft on humanitarian assistance backed by Western and Arab states "is prepared in the form of an ultimatum. There are threats of sanctions."
The co-sponsors of the Geneva talks, Russia and the United States, are to meet on Thursday with UN-Arab League mediator Brahimi.
But the rival delegations said they had no new meetings scheduled during the day.
On the ground, the violence rages.
The Observatory said explosive-packed barrel bomb attacks and fighting in Aleppo killed at least 51 people on Wednesday.
Thirty-eight, including seven children, were killed by barrel bombs in opposition areas of what was once Syria's commercial capital.
Rights groups have repeatedly condemned the regime's use of helicopter-borne barrel bombs as "indiscriminate".
In Daraa in the south, 31 people were killed, again mostly in barrel bomb attacks, the Observatory said.
Around 20 air strikes on Yabrud and nearby fighting pushed some 400 families to flee for shelter to Arsal in neighbouring Lebanon, the UN refugee agency's Dana Sleiman said via Twitter.
The latest daily death tolls in Syria have been the highest since the war began nearly three years ago and coincide with the peace talks.
According to the Britain-based Observatory, 5000 people have died in just three weeks.
The monitor, which relies on information from activists and medics inside Syria, says at least 136,000 people have been killed since the conflict erupted in March 2011.