A senior Russian officer said - late on Sunday evening - that Russian and Syrian forces killed 20 "Islamic militants" in an operation in Daraa (southern) Syria, while calm returned to the city of Afrin (north), which is under the control of the opposition forces, a day after a truce It was reached with Turkish mediation, which ended bloody clashes between rival Syrian factions.

The Russian Tass news agency quoted Major General Oleg Egorov as saying that among the dead were those responsible for the bombing of a bus of Syrian army soldiers, which killed at least 18 soldiers.

Egorov added - in a press briefing - that the Russian group concerned with interacting with the security units of the Syrian armed forces carried out a special operation in the town of Jassem in Daraa province, southern Syria, to liquidate ISIS fighters.

News agencies could not independently verify these reports.

The bus attack was one of the deadliest attacks targeting the regime forces of Syrian President Bashar al-Assad in months.

No one immediately claimed responsibility for the attack, and there was no comment from the Syrian authorities.

Russian forces have been deployed in Syria since 2015, and have aided the authorities in their campaign to retake rebel-held territory.

In a related context, a video clip - published by Syrian activists - showed the moment of Russian air strikes in conjunction with artillery shelling by the regime forces on the Urm al-Jawz area in the southern countryside of Idlib in northern Syria, this morning, Monday.

Calm in Afrin

In Aleppo province, residents and opposition fighters said that calm prevailed - yesterday, Sunday - in the city of Afrin, which is under the control of the opposition forces, a day after a truce - brokered by Turkey - ended bloody clashes between rival factions that were threatening to erupt a wider internal war between opponents of the president’s rule. Bashar al-Assad.

Under the initial agreement, Hayat Tahrir al-Sham - which the United States, Turkey and others included among the terrorist organizations - withdrew its forces from the city of Afrin, which it entered last Thursday, in exchange for the pledge of its opponents in the national army to work on establishing a unified civil administration that achieves stability and ends chaos.

Negotiators said the two main opposition factions, the Levant Front and Jaish al-Islam, which operate under the umbrella of the National Army's Third Corps, had agreed to return to their fronts and dismantle their military presence in urban centers.

Wael Alwan, a former official in the Syrian opposition and a researcher at the Jusoor Center for Studies, based in Istanbul, said, "In the recent battles after taking control of Afrin, Hay'at Tahrir al-Sham now has a major security role compared to what it used to be. It also aspires to expand further."

Julani's goal

Armed opposition sources said the agreement brings the leader of Hayat Tahrir al-Sham, Muhammad al-Julani, closer to his goal of expanding a civilian administration that now efficiently runs public services in the Idlib region to other areas, in an attempt to get rid of the hard-line image of the former Syrian branch of al-Qaeda.

Turkey is the main supporter of the main opposition fighters, and its strong military presence in northwest Syria has prevented Moscow and Damascus from seizing the rest of the opposition areas.

A senior rebel commander, who asked not to be named, said Turkey had stepped up its intervention to end the fighting that has killed dozens.

Turkey fears that Hay’at Tahrir al-Sham’s control of a large part of northern Syria will give Moscow the freedom to renew the continuous bombing of the area inhabited by more than 3 million displaced Syrians, who fled Bashar al-Assad’s rule under the pretext of fighting “extremists.”

Two leaders of the opposition fighters said that Russian warplanes bombed - on Sunday - the village of Kafr Jana, which was the scene of some of the fiercest battles between the opposition fighters, in a message from Moscow that it will attack without deterrence the areas that are now under the broader influence of Hay'at Tahrir al-Sham.