UN observers plan to return to the Syrian village of Tremseh to continue their investigations into an attack on Thursday that killed up to 200 people, BBC reports.

The observers' visit on Saturday confirmed the use of heavy weapons and that the government attack appeared to target rebel fighters.

Initial findings appeared to contradict reports of a civilian massacre.

However, the observers were unable to determine how many died, who they were or exactly who carried out the attack.
The Tremseh killings appear to differ from the situation at Houla two months ago, when UN observers were able to arrive quickly and count the bodies of what was clearly a massacre.

BBC correspondent says the observers arrived in Tremseh 48 hours after the attack, all they could conclude was that it appeared to target rebel fighters or defectors from the Syrian army.

But our correspondent says the confirmation of the use of heavy weaponry explains the angry responses from UN Secretary General Ban Ki-moon and the UN and Arab League special envoy for Syria, Kofi Annan.