THE ceasefire which came into effect this morning appears fragile after claims of killings by both rebels and government led forces.
News reports from the region are claiming the ceasefire has been broken, with one report claiming that a 'terrorist' attack in Aleppo has killed one soldier, and another that three civilians have been killed by Assad forces.
State media claimed that "terrorists" planted a roadside bomb which they claim has killed one officer: At eight in the morning a terrorist group targeted a bus carrying a number of officers driving to work in Aleppo.
Syria opposition claim that three civilians were killed and dozens arrested since ceasefire.
According to reports from the ground two of the victims were in the Hama region and there were arrests in Aleppo and Daraa, Basma Qoudmani said, adding, "We have visual proofs, videos and photos that heavy weapons are still in populated areas."
Earlier, Kofi Annan, the United Nations envoy and architect of the ceasefire proposal, said he had received a promise from Mr Assad's government that it would "cease all military fighting throughout Syrian territory" at 6am local time, in accordance with the plan.
Syrian state television read out a similar pledge. "After our armed forces completed successful operations in combating the criminal acts of the armed terrorist groups and enforced the state's rule over its territory, it has been decided to stop these operations from Thursday morning," it said.
A "few explosions" were heard in the town of Zabadani, just outside the capital, shortly after the ceasefire entered into effect, Abdel Rahman of the Syrian Observatory said.
"There has not been any movement indicating a withdrawal of tanks," he added.
However, world powers were discussing back-up plans for the crisis last night in Washington, with many assuming that the ceasefire would fail.
William Hague, the British Foreign Secretary, said Britain would boost support for opposition forces and seek tougher sanctions if terms of the ceasefire were breached.
"Our pressure on the regime - its campaign of murder, torture and oppression - must be intensified if Kofi Annan has not succeeded," Mr Hague told reporters.
David Cameron, the UK Prime Minister, was due to speak directly to Mr Annan, who will have to decide whether to call an end to his own six-point peace plan or allow it more time.
Activists said that the regime had used the build-up to the ceasefire, supposed to include a withdrawal of all troops from towns and cities, to make further raids, arresting activists and bombarding rebellious areas.
"We always knew this was the Assad plan," said one activist. "We would be forced to hold back while he carried on his attacks. We fell into his trap but we had no choice."
Activists and video reports talked of shelling and other military action in Homs, Rastan, Deir al-Zour and other cities across the country.
Hillary Clinton, the US secretary of state, was due to meet her Russian counterpart, Sergei Lavrov, on the eve of a meeting of Group of Eight foreign ministers to press him to change Moscow's stance.
Meanwhile, Turkey's foreign minister, Ahmet Davutoglu, who returned early from a trip to China to deal with the crisis, said he would address all G8 ministers by video conference.
Turkey is said to be considering creating a buffer zone for refugees which could become a base for armed opposition to the regime, even if its original intention were only to protect Turkish territory. Syrian troops fired over the border for the third day in a row, according to refugees in the Kilis camp nearby who showed off bullets that had thudded into the camp earlier.
A member of the Free Syrian Army who called himself Omar said he had been shot by Syrian troops as he ventured into no-man's land between the two frontier posts to try to retrieve the body of a rebel killed earlier.
"I saw him lying on the ground beside the Turkish flag that marks the border," Omar said. "I came within one hundred meters of the body and snipers from Assad's army started shooting. They shot me three times, once in each leg and once in my side."
If Mr Annan says the ceasefire has been met, western powers will come under pressure to persuade the opposition to join talks with Mr Assad, which they have vowed not to do. But they will also point out that as well as representing the United Nations, Mr Annan is formally the envoy of the Arab League, whose demand that Mr Assad hand over power to his deputy and hold free elections has not been withdrawn.