Russian bombing raids have murdered more than 50 Turkish-backed militiamen in the largely rebel-held Idlib province.
A group’s training center named Faylaq al-Sham was attacked. The strike, which marks an increase in violence in the area, has harmed many others.
The attack puts a truce in Idlib at risk, brokered and supervised by Russia and Turkey, backing the war on different sides.
The Syrian Observatory for Human Rights, a UK-based monitoring group, estimated the number of murdered at 78.
The Observatory added that some of the injured were in critical condition, and the number of deaths was likely to increase.
The attack is reported to be the deadliest since the ceasefire happened to start in March.
The truce brought to an end a Syrian government hostile on the area which had dislodged just about 1,000,000 individuals and has to a great extent held from that point forward.
Upon the declaration of the ceasefire, Turkey told reporters it retains the right to “retaliate with all its strength” if any attack happens by the forces of President Bashar al-Assad.
Idlib is the last region to be controlled by rebels and jihadists who, in a nine-year civil war, were beaten back.