The Russian Foreign Ministry confirmed the attack in a statement on Thursday, saying mortar fire struck the embassy.
The statement blamed foreign-backed militants in Syria for the attack, adding that no Russian nationals were hurt in the incident and that the building was slightly damaged.
Reports also said that two bomb explosions followed the mortar attack.
Militants have targeted the Russian Embassy several times since the beginning of unrest in Syria. They are angry over Russian government’s continued support for the government of President Bashar al-Assad.
On September 22, three people working at the embassy received injuries after the projectile landed in the compound of the diplomatic mission.
On June 4, at least one civilian was killed and several others injured near the Russian Embassy in Damascus by shellfire from militants fighting against the Syrian government.
The embassy was damaged in February when a car bomb exploded nearby on a busy Damascus highway, killing 50 people.
Syria has been gripped by deadly unrest since 2011. According to reports, the Western powers and their regional allies — especially Qatar, Saudi Arabia, and Turkey — are supporting the militants operating inside Syria.
According to the United Nations, more than 100,000 people have been killed and millions displaced in the violence.