At least 23 people have been killed by Russian air strikes overnight on the rebel-held city of Idlib, in north-western Syria, activists say.
The Syrian Observatory for Human Rights said various positions were targeted, one of them next to a hospital.
The UK-based group added that seven children were among the victims and the death toll was expected to rise.
Idlib city and the province of the same name are a bastion of groups including the al-Qaeda-linked Nusra Front.
The Nusra Front is excluded from a partial cessation of hostilities brokered by the US and Russia in February to make way for a resumption of peace talks.
The Syrian Observatory said the attacks also hit several residential areas and there were strikes near a public garden.
Pictures showed buildings destroyed and rescue teams working through the night searching for casualties.
Russia is a key ally of Syrian President Bashar al-Assad and has carried out an air campaign that it says targets “terrorists”.
Meanwhile, the Turkish foreign ministry said the death toll in the strikes was above 60, and that 200 people had been injured.
In a statement, it called on the international community to act against what it called the “indefensible” crimes of the Russian and the Syrian administration.
Turkey has strongly criticised the Russian operations in Syria and opposes the Assad government.