London, July 27 (RHC)-- A UK-based monitoring group says at least 29 people have been killed in US airstrikes in the Syrian city of Raqqah. "At least eight children are among the dead," said the director of the so-called Syrian Observatory for Human Rights, Rami Abdel Rahman, on Wednesday.

The observatory noted that the recent airstrikes brought the civilian death toll to at least 325, including 51 children, in the two months since the U.S.-backed Syrian Democratic Forces began operations to liberate Raqqah from the Daesh Takfiri group.

The U.S.-led coalition has been conducting airstrikes against what are said to be Daesh targets inside Syria since September 2014 without any authorization from the Damascus government or a UN mandate. The military alliance has repeatedly been accused of targeting and killing civilians. It has also been largely incapable of fulfilling its declared aim of destroying Daesh.

The monitoring group also noted that the Syrian Democratic Forces (SDF), an alliance of Kurdish and Arab fighters, "are now in control of 50 percent of Raqqah despite the fierce resistance mounted by Daesh."

The city of Raqqah, which lies on the northern bank of the Euphrates River, was overrun by Daesh terrorists in March 2013, and was proclaimed the center for most of the Takfiris’ administrative and control tasks the following year.

An SDF spokeswoman also confirmed that they are now in control of almost half of the city and that the Takfiri terrorists are putting up fierce resistance.

Syria has been fighting different foreign-sponsored militant and terrorist groups since March 2011. UN Special Envoy for Syria Staffan de Mistura estimated last August that more than 400,000 people had been killed in the crisis until then.