DAMASCUS, Syria

A senior commander of Syrian opposition group Jaysh al-Islam, Zahran Alloush, has been killed in an airstrike following a meeting in Damascus, sources in Eastern Ghouta told Anadolu Agency Friday.

According to the sources, the attack targeted the group's headquarters in Marca al-Sultan neighborhood.

Alloush was reportedly holding a meeting with his advisers and high-ranking commanders when the attack took place.

The sources said the sound of a warplane was not heard prior to the attack and it is possible the airstrike was launched from a high altitude.

Russia's Ria's Sputnik International quoting local sources said the attack was carried out by Russian warplanes; however, the Kremlin was yet to officially confirm that the attack was carried out by one of its aircraft.

Jaysh al-Islam, or Army of Islam, is considered one of the largest armed opposition groups in Syria, which has significant presence in eastern Ghouta.

Syria’s ongoing civil war, now in its fifth year, has led to the death of at least 250,000 people and made the country the world's single-largest source of refugees, according to UN figures.