At least 42 people, including 27 civilians have been killed in Russian air strikes in the DAESH-held northern Syrian town Raqqa earlier this week, a monitoring group said on Friday.
The Britain-based Syrian Observatory for Human Rights (SOHR) said that 15 DAESH terrorists made up the remainder of the death toll from the air strikes.
Raqqa province is the main stronghold of DAESH in Syria, after they announced it as the capital of their claimed caliphate state in 2014.
Another monitoring group, the Syrian Network for Human Rights, said on Monday that the death toll of civilians killed by the Russian air strikes has reached 254 people in just over a month.
Russia, the main ally of Syrian regime leader Bashar al Assad, started its air campaign in Syria targeting Assad’s opponents on September 30, forcing more than 120,000 Syrians to leave their homes.
The US, who is leading another air campaign in Syria, has accused Russia of targeting US-trained “moderate Syrian opposition,” fighting against Assad’s regime - focusing on the west and northwest of the country.
US officials said that Moscow's military force in Syria has grown to about 4,000 personnel, claims which Russia denies saying that only Russian military experts are involved on ground.
The UN estimates the death toll in Syria, since the war started as an uprise, to be at least 250,000, while the SOHR states that the number have now reached 350,000.
A further estimate of 350,000 refugees have sought asylum in European Union countries since the war began in Syria in 2011.
About 4 million others took refuge in neighbouring countries of Turkey, Lebanon, Iraq and Egypt, with Turkey hosting the largest group with over 2 million.
Thousands are still pushing towards EU countries which caused a global refugee crisis urging for an immediate solution in Syria.
Around 1,650 sorties have been flown by Russian war jets and 2,084 militants have been struck since the start of the campaign according to the Russian Air Force, Reuters reported.