Syria's opposition coordinator Riad Hijab has accused Russia of killing dozens of children in bombing raids and said such action meant the opposition could not negotiate with President Bashar al-Assad's government.
Hijab was speaking on Monday after at least 15 people were killed, including 12 children, in a suspected Russian attack in Syria's Aleppo province.
"We want to negotiate, but to do that the conditions have to be there," Hijab told reporters. "We cannot negotiate with the regime when there are foreign forces bombing the Syrian people."
Hijab put the death toll at 35 children and said the Russian strikes had hit three schools in total.
The former Syrian prime minister who defected to the opposition in 2012 was in Paris for talks with French President Francois Hollande, the Reuters news agency reported.
There was no immediate comment from Moscow, which denies any targeting of civilians in the conflict.
The death toll from Monday's strike in Ain Jara, 15km north of Aleppo city, was expected to go up as some of the survivors died of their injuries, the UK-based Syrian Observatory for Human Rights said.
An Al Jazeera correspondent at the scene said rescuers were continuing to search for survivors in the rubble after the attack, that happened in rebel-held territory.
The attack is the latest deadly incident blamed on the Russian military, with nearly 100 people reported killed in a series of air raids on the town of Maarat al-Numan in Idlib province on Saturday.
Peace talks are scheduled to be held between the government and opposition on January 25 under the auspices of the United Nations.
However, opposition officials have already cast doubt on whether the talks will go ahead on schedule, citing a need to see goodwill measures from the government side.
Source: Al Jazeera And Agencies