Rami Abdelrahman, the organization founder, said that six of the casualties were from the same family.
"I sent our activists to hospital there, we have video [of the corpses], but we haven't published it because there are children [involved]," he said.
The Local Coordination Committees, a network of Syrian activists, supported the claim, reporting that one of the children was as young as six.
A senior Turkish official claimed that the incident is currently under investigation by Turkish authorities, who, however, were "unable to independently verify the claims".
"Turkey provides humanitarian assistance to displaced persons in northern Syria and follows an open door policy, which means we admit refugees whose lives are under imminent threat," the official said on condition of anonymity in line with government regulations.
According to the Syrian Observatory for Human Rights, total of 60 Syrians were killed on the border since the start of the year.
Turkey reportedly hosts 2.7 million Syrian refugees — more than the rest of the world combined, and more refugees (3 million total) than any other country.
However, Syrian refugees reportedly face significant challenges in Turkey, as most of them are effectively not permitted to work in Turkey, and hundreds of thousands of Syrian children do not have access to education.