A six-point peace plan for Syria brokered by UN-Arab League envoy Kofi Annan looked ready to unravel on Monday.
Syrian president Bashar al-Assad's army and opposition forces locked horns in a war of words over Annan's proposed troop withdrawal as reports of new atrocities emerged.
Reports continue to emerge Syrian troops beating and burning people to death, as well as summary executions of wounded rebel fighters and suspected sympathizers.
According to rights activists, at least 85 of those killed Monday were not involved in fighting, including women and children.
Originally, Syria had agreed to the plan laid out by Mr Annan, the former United Nations secretary-general, in which troops and tanks were to be withdrawn by today, with a ceasefire to take effect 48 hours later.
However, Syria's Foreign Ministry on Monday added new demands for written guarantees from opposition fighters that they will lay down their arms before troops are withdrawn.
The Syrian National Council responded saying it would provide written assurance of a ceasefire, but commanders of the Free Syrian Army said they would only negotiate with international mediators and not Assad's regime.
Al-Jazeera television reported clashes last night between the Free Syrian Army and troops loyal to the president near Eazaz on the Turkish border.
Human rights activists reported six Syrian officers were killed in battles on the Turkish border, and that eight defecting soldiers were wounded before they crossed into Turkey.
Syrian forces also fired across the border at protesters in a refugee camp in Turkey, in the first such attack since Turkey began sheltering thousands of refugees last summer.
Two refugees and one Turkish citizen, a translator, were wounded inside the camp near the town of Kilis in south-western Gaziantep province, a Turkish official said.
Turkey has lodged a formal complaint with Syria's government and demand the fire across its border end immediately.
International analysts say Assad is aware the week position of opposition fighters gives Annan and his international backers little leverage as he presses forward with the brutal year-long crackdown that has claimed at least 9,100 lives.
Meanwile, a Human Rights Watch report released yesterday catalogued details of more than 100 executions, many of them in the past month. It gives details of the involvement of Syrian forces and pro-government shabeeha militias in summary and extrajudicial executions in Idlib and Homs.
''They are doing it in broad daylight and in front of witnesses, evidently not concerned about any accountability for their crime,'' a researcher at Human Rights Watch, Ole Solvang, said.
Human Rights Watch has urged the UN Security Council to refer the situation in Syria to the International Criminal Court.
UN Human Rights chief Navi Pillay has already gone on record saying there is ample evidence to prosecute Assad at the International Criminal Court for war crimes.