A new US and Russian backed ceasefire across Syria officially began at 7pm on Monday, but both opposition fighters and pro-government media have said that violations have already taken place.
Residents and media activists in besieged East Aleppo reported that Syrian government helicopters bombed at least one neighbourhood at approximately 8pm, an hour after hostilities were supposed to cease.
In Quneitra in the south of the country, state media said four Syrian army solidiers had died in a rebel group attack.
The fragile ceasefire is supposed to reduce violence over the next week, before new US and Russian airstrikes begin on extremist groups such as Isis and al-Qaeda allied militants. Negotiators have not publicly stated what geographical areas will be targeted, raising concerns among both the official Syrian opposition and Kurdish militias.
Long term hopes for peace in the five-year conflict were further complicated by an Eid address from Syrian president Bashar al-Assad, just hours before hostilities were due to cease, in which he vowed to retake the entire country from rebel hands.
US Secretary of State John Kerry also caused confusion on Monday evening by saying that the US could be in a position where it approves Syrian government airstrikes against al-Qaeda affiliates. The State Department has since walked back his comments.
Speaking to reporters in Washington DC, Kerry also said that some breaches of the agreement could be expected.
The last US and Russian brokered ceasefire came into effect in February, but broke down in a matter of weeks.
Fighting did not wind down before before the ceasefire came into effect: approximately 100 civilians are thought to have been killed over the weekend in fierce fighting mostly around the rebel-held city of Idlib.
On Tuesday, Syrian media claimed the army had shot down both an Israeli fighter jet and drone in the Golan Heights, the disputed border area between the two countries. Israel denies it has lost any aircraft.
