Several houses could be seen destroyed, their interiors pock marked by holes suggesting heavy rifle and rocket propelled grenade fire. Bloodstains could be seen on the walls, floors and furnishings.
The monitors, on a second visit to Tremseh since the attack, interviewed 27 villagers and said their consistent accounts were that the village came under attack at 5am on Thursday morning. It began with shelling of the village, followed by ground operations apparently targeting defectors and opposition activists.
The observers also confirmed the use of artillery and mortars as well as small arms fire. The team was unable to confirm the number of casualties.
On Sunday, Syria denied that it had used heavy weapons or helicopters in Tremseh, saying the heaviest weapons used were rocket propelled grenades, during clashes between security forces and what they described as "heavily armed forces that don't believe in a political solution".
Special envoy Kofi Annan, who is leading efforts to implement a peace initiative in Syria, said that the government had violated its commitments to UN-backed peace efforts.
Contains footage from Reuters
