As many as 485 of the total deaths were civilians, as the rest were militants with the Islamic State group or the al-Qaida-linked Nusra Front, according to the Syrian Observatory for Human Rights.
It said the toll was the result of thousands of Russian air strikes on several Syrian areas, since the Russian air force started striking the militants' positions in Syria late last September.
Russian officials have repeatedly said the Russian warplanes target only the terrorist groups, as part of Moscow's declared war on terror in Syria.
Syrian government officials have hailed the Russian air raids as effective, adding that the strikes enabled the Syrian army to advance on the ground.
A well-informed official Syrian source told Xinhua on Monday that the Russian air force was using advanced reconnaissance system in Syria, adding that they use such technics before carrying out air strikes to make sure the targets are only militant groups.
Speaking on condition anonymity, he said the rebels try to accuse Moscow of targeting civilians to tarnish the Russian anti-terror campaign.(IANS)