The defense ministry said violations were committed by moderate rebels as well as “terrorist organisations”.
“The United Nations, the United States and Russian Federation have made a positive assessment of the first hours of the cessation of hostilities“, a western diplomat said after a meeting of the International Syria Support Group (ISSG) in Geneva.
While many Syrians are enjoying the relative calm of a ceasefire, that quiet was broken in several towns hit by airstrikes Sunday, a day after the cessation of hostilities went into effect.
The ministry highlighted an attack on the town of Tal Abyad on the border with Turkey.
They said they were able to repel the attack but that clashes were ongoing.
Moscow said it had demanded an explanation from the United States, which leads an anti-Islamic State coalition that includes Turkey. “On the whole, the ceasefire regime in Syria is being implemented”, it said of the deal.
Previous attempts to end the fighting have failed and Russian Federation and the U.S., which back opposing sides in the fight, have warned that applying it on the ground will be hard.
According to the British-based Syrian Observatory for Human Rights the identity of the jets was not clear.
Syria’s state-run news agency reported Saturday afternoon that rebel factions in Damascus suburbs had fired shells on residential areas of the capital, the first time the government accused opposition groups of violating the agreement.
“If it (the truce) holds, it will create the conditions for full, sustained and unimpeded humanitarian access throughout Syria“, said European Union foreign policy chief Federica Mogherini.
The Observatory said intense fighting is ongoing near the northern town of Khanaser between pro-government forces and IS.
Quoting the head of the coordination centre, the agency says Moscow has contacted a United States centre in Amman for clarification.
Guns fell silent across Syria on Saturday after a landmark UN-backed ceasefire came into effect, the first major truce in five years of civil war that have claimed more than 270,000 lives. However, insurgent groups have reported shelling from Russian planes in Aleppo.
Hezbollah said Monday the body of Ali Fayyad, known locally as Haj Alaa, was recovered Sunday night in an operation in which Syrian army and Hezbollah special forces took part.
But it has vowed to keep striking IS and al-Nusra and other “terrorist groups“.
The exclusion of the Islamic State from the deal is significant, since the group controls large areas of the country.
The head of that center, Sergei Kuralenko, said, according to Reuters, that the truce “in general” is holding despite these violations. “The ceasefire will continue, God willing”, he said.
Yet, some rebels claimed that there were what they called occasional violations in Hama province on part of government forces.
He said 74 opposition units including more than 6,100 fighters have agreed to adhere to the truce.