Warplanes believed to be Russian on Friday carried out several air strikes on areas of northwestern Syria that were included in a ceasefire agreed by warring sides in September, the Syrian Observatory for Human Rights said.
 
 
The strikes hit the outskirts of the towns of Maarat Masrin and Ram Hamdan in Idlib province, the Observatory said. It was the first time warplanes had bombed that area, it said.
 
 
The ceasefire has largely held despite minor, isolated violations.