At least 73 civilians, including 22 children and nine women, were killed in suspected Russian airstrikes on IS-controlled areas in eastern Syrian, a monitoring group said.

At least 29 civilians were killed when the suspected Russian fighter jets hit the village of Khasham on Saturday in the volatile Deir Ezzor province, the Syrian Observatory for Human Rights said in a statement.

Meanwhile, the group has also stated that it is not clear weather the airstrikes were carried out by Russian or Syrian government warplanes.

The deadly airstrike on Khasham, which lies merely 14 miles from the provincial capital Deir Ezzor, comes a day after 44 civilians, including at least a dozen children, were killed in bombardments in the neighboring village of Tabiyyah Jazeera, Al Jazeera reported. It is also unclear whether Friday's airstrikes were carried out by Russian or Assad's forces, the group said.

At least 32 people were killed in similar airstrikes on IS locations in Raqqa, the capital of the self-declared Caliphate.

The latest airstrikes are part of regime's fresh offensive to retake territory captured by ISIS in the eastern part of the country. ISIS militants have also started retaliatory attacks on regime forces around the provincial capital.

The latest assault and fighting reportedly claimed nearly 500 lives in the Deir Ezzor province, according to the Middle East Eye.