Assad killed at least 15 people overnight in a Sunni Muslim village north-west of the city of Hama, activists said on Saturday.
The Syrian Observatory for Human Rights said a woman and two children were among those killed in the attack in the village of Sheikh Hadid by soldiers and pro-Assad militia.
The British-based group, which monitors violence in Syria through a network of activists and medical and security sources, said the killings followed attacks by rebels on military checkpoints in the area over the previous two days.
It said 26 people - 16 soldiers and 10 members of the pro-Assad National Defense Force - were killed when rebels attacked a nearby checkpoint on Thursday. There was also fighting in the village of Jalma, two miles (3 km) south of Sheikh Hadid, on Friday, it said.