US and Russian monitors insist the fragile truce in Syria is holding, despite a number of violations.
Officials say the agreement has been breached at least 9 times in 24 hours.
It came into force just after midnight in the early hours of Saturday.
What about the airstrikes on Sunday morning?
News of attacks on six villages in the Aleppo area came from Syrian insurgents.
They claim the planes involved were of Russian origin.
This has not been officially confirmed.
The Syrian Observatory for Human Rights says some of the villages were controlled by the Nusra Front and other Islamist groups.
The Russian coordination centre in Syria says it has received information of an attack from Turkish territory on the Syrian town of Tel Abyad.
The news comes from the Interfax agency, quoting the Russian Ministry of Defence.
Quoting the head of the coordination centre, the agency says Moscow has contacted a US centre in Amman for clarification.
Damascus
Shellin
