Syrian rebels killed at least 80 army soldiers in a surge of attacks at the weekend that followed their threat to resume fighting if President Bashar al-Assad failed to observe a United Nations-backed ceasefire.
Free Syrian Army fighters said they had killed "more than 100 soldiers" and "destroyed some tanks" in clashes across Syria, including Damascus and Idlib province in the northwest.
Syria's state news agency reported the burial on Monday of 30 members of the security forces killed by rebels.
The Syrian Observatory for Human Rights said local doctors had confirmed the names of 80 dead government soldiers.
The new uptick in violence coupled with Assad's defiant speech to parliament on Sunday has raised questions about how long UN envoy Kofi Annan can push his floundering peace plan.
Some FSA commanders announced last week they would be "free of any commitment" to Annan's peace plan if Assad did not end violence by Friday.
However, the overall commander of the FSA, col. Riad al-Assad in Turkey, had asked Annan to admit failure and release the fighters from their ceasefire obligations.
Annan, who has sent 300 United Nations observers into Syria to verify the clearly non-existent truce, is expected to brief the Security Council on Thursday.
A Syrian troop pullback was at the top of Annan's six-point plan to halt hostilities, allow peaceful protests, supply humanitarian aid and start a political transition in a country under 42 years of autocratic rule by the Assad family.
The renewed FSA offensive was precipitated the May 25 massacre of at least 108 people – including 49 children and 32 women – in the Houla area of Homs province.
Following the Houla massacre – which witnesses cited by UN investigators say was perpetrated by Assad-allied Shahiba gunmen – most Western diplomats have admitted the Annan plan, even if he won't admit it, is already dead.
Western powers have no desire for Libya-style military action, but have provided no alternative to Annan's efforts. Nonetheless, it has been reported Washington may move to arm the FSA.
Russia and China, both with billions of dollars tied to the Assad regime that could be lost in the political aftermath of a Western intervention, say Annan's plan is the only way forward.
They have twice blocked UN Security Council resolutions which would have condemned Damascus.
Assad has rebuffed criticism of the carnage his forces have wrought, saying Sunday "When a surgeon performs an operation to treat a wound, do we say to him: 'Your hands are covered in blood'? Or do we thank him for saving the patient?"
Syria's popular uprising, inspired by Arab revolts elsewhere, began with peaceful protests calling for political reform rather than Assad's ouster. That changed, however, following Assad's brutal repression.
In the 14-months since March 2011, local rights observers say 13,000 have been killed – most of them civilians. At least 1,000 have been killed since the April 12 ceasefire date.