At least 35 people were killed Monday in airstrikes in and around the northern Syrian city of Aleppo, thought to have been carried out by the government or its Russian ally, a monitoring group and medical officials said.
At least 23 people died in airstrikes on the rebel-held village of Ouwayjel, about 18 kilometres west of Aleppo, the Syrian Observatory for Human Rights reported.
The new raids came a day after the US and Britain said they were considering new sanctions against Russia and the Syrian government in response to the siege of rebel-held eastern Aleppo.
Talks on the conflict between the foreign ministers of Russia, the US, Turkey, Saudi Arabia and Qatar ended inconclusively in Switzerland on the weekend.
A doctor in Ouwayjel told dpa that more than 60 other people had been wounded in the village. Local activists said Russian planes had carried out the strikes.
Earlier, at least 12 civilians, among them five children, were killed Monday when Russian and regime planes raided areas in rebel-held eastern Aleppo city, the Observatory said.
Ibrahim al-Hajj, spokesman of the White Helmets rescue group in eastern Aleppo, told dpa that the raids were allegedly conducted by Russian planes using "new bombs which we called earthquakes due to the loud bangs and massive damage they make."
Al-Hajj put the toll at 14, including eight children.
According to the Observatory, some 702 civilians, including 141 children, have been killed in and around Aleppo since a brief ceasefire collapsed on September 19.
The majority of deaths were in rebel-held eastern Aleppo, a total of 448 civilians, the Observatory said. The government-held western sector has also been repeatedly targeted by indiscriminate rebel shelling.
Russia intervened in Syria a year ago to prop up President Bashar al-Assad's crumbling army.
Its air campaign has enabled government forces to reclaim territory from both rebels and the Islamic State extremist group.
Some 250,000 to 300,000 civilians are thought to be trapped in eastern Aleppo, with dwindling food supplies and extremely limited medical care in underground hospitals that have themselves repeatedly been hit in airstrikes.
Elsewhere, a booby-trapped car exploded as it was being searched by Syrian soldiers at a checkpoint in Saboura west of the capital Damascus, killing two soldiers as well as the driver, a Syrian security source said.