UN Supervision Mission in Syria has entered Tremseh once again to assess the casualties and damage in the village where an attack took place on Thursday.
"We are in Tremseh now we entered today at 08:30 (05:30 GMT). we are continuing to verify the facts and if we have more we will inform you", Sausan Ghosheh, UNSMIS Spokeswoman said on Sunday in Damascus.
UNSMIS published a statement on Saturday in which they confirmed that an attack took place in the village.
The statement added that heavy weapons were used as well as helicopters.
"We can confirm that there was a military operation on July 12th on Thursday. The attacks appeared targeted towards specific homes of activists as well as army defectors. UN team observed homes which had pools of blood and blood splatters in some of the rooms as well as empty bullet cases. There was a wide range of weapons used including heavy weapons and artillery mortars and small arms", Ghosheh added.
The statement did not identify the perpetrators of Thursday's attack or estimate the number of dead. Opposition activists have said between 100 and 200 rebels and civilians were killed.
The Tremseh attack has triggered a global outcry against the regime of President Bashar al-Assad, with UN chief Ban Ki-moon calling for "decisive" action to stop the bloodshed.
Another group of UN observers headed to Douma on Sunday in order to hold a humanitarian visit to hospitals and schools and assess the effect of the 16-month crisis in the country.
Activists said that at least nine people were killed on Sunday in new violence across Syria, including two civilians when troops shelled the flashpoint city of Homs as they tried to seize control of several neighbourhoods.
On Saturday a pregnant woman was among 115 people -including 50 civilians- killed across Syria, activists reported.
Meanwhile, the outskirts of the northern commercial hub of Aleppo came under intense bombardment on Saturday, according to an AFP news agency reporter and a rebel official.
In the southern province of Deraa, activists on Saturday said that troops and militias had stormed and torched the southern town of Khirbet Ghazaleh.