Russia’s Defense ministry denies fighting of Syrian government and opposition units

However, it is clear that the Astana agreement is a responsibility.

There were also reports of shelling and gunfire in other parts.

Russian Deputy Defence Minister Alexander Fomin said on Friday that there had been no bombing raids by Russian aviation in the four zones since 1 May.

Russian Federation says maps delineating the zones should be ready by June 4.

On Friday, Russian media reports cited Russia’s General Sergei Rudskoi, head of the main operational directorate of Russia’s military, as stating that the agreement brokered by Moscow, Ankara and Tehran to establish “de-escalation zones” in main battlefields in Syria will go into force as of midnight Saturday.

The six-year old Syrian civil war has resulted in the death of at least 400, 000 people, with half of the population said to have fled the country since.

No Syrian party has signed onto the deal. But the armed opposition was highly critical of the proposal, saying it lacked legitimacy.

De-escalation zones have also been established in Idlib province and parts of Latakia, Homs, eastern Ghouta, near Damascus, and the south of the country on the border with Jordan.

In the tangled mess that constitutes Syria’s battlefields, there is much that can go wrong with the plan agreed on in talks Thursday in Kazakhstan.

With the help of Russian Federation and Iranian-backed militias, the Syrian government has gained the military upper hand against rebel groups, including some supported by Turkey, the US and Gulf monarchies.

The United States and Russian Federation will resume an airspace deconfliction agreement aimed at avoiding mid-air collisions, Reuters reported Saturday. According to the memorandum, any clashes between the government forces and opposition armed groups must stop within the zones.

By Saturday morning “relative calm” was reported in the four de-escalation zones by both government and opposition officials. Turkey supports Syrian opposition forces.

The Observatory said it had not recorded any deaths as a result of fighting in the four zones since midnight, but there had been some violations. It was not immediately clear if the fighters were members of the al-Qaida-linked Levant Liberation Committee that is usually excluded from cease-fires.

Doyle said there are huge question marks over the commitment of various actors to reducing violence and over how the plan will be enforced.

Syrian, Russian, Turkish and US -led coalition aircraft sometimes operate in the same areas in Syria.

Those zones would see a halt to hostilities, including air strikes.

Lavrentyev, whose remarks were carried by Russian news agencies, said US -led coalition aircraft would be able to operate against Islamic State of Iraq and Syria (ISIS) militants in specific areas, but the “de-escalation zones” were now closed to their flights.

The spokesman, Mr Edgar Vasquez, said Russian officials’ interpretation of their own agreement “makes no sense”.

The initiative was proposed by Russia, President Bashar al-Assad’s most powerful ally, with the support of Turkey, which backs the opposition.

Osama Abo Zayd, a spokesman for the Syrian military factions at the Kazakhstan talks, said in an interview that it was “incomprehensible” for Iran to act as a guarantor of the deal. They also include some of the areas where Turkey, a North Atlantic Treaty Organisation ally, has skirmished with Kurdish militias that are backed, sometimes with airstrikes, by the United States.