At least 47 civilians, including children, were killed Saturday in airstrikes targeting areas under the control of the Islamic State terrorist militia in eastern Syria, a monitoring group said.
Jets, believed to be Russian, struck the area of Khsham on the eastern outskirts of Deir al-Zour province, the head of the Syrian Observatory for Human Rights, Rami Abdel-Rahman, told dpa.
The latest deaths bring to at least 91 the number of civilians killed since Friday in airstrikes in the province, according to the Britain-based observatory.
There was no official comment from the government in Damascus.
Islamic State controls most of Deir al-Zour and has been been besieging regime-held areas in the province for more than a year.
Russia, an ally of Syrian President Bashar al-Assad, launched an air campaign in Syria in September, saying its targets were the Islamic State and other extremist groups operating there.
Separately, the United States has been leading an international air campaign in the war-torn country since September 2014.
At least 4,272 people, including 315 civilians, have since been killed in airstrikes in Syria, the Observatory reported on Saturday.
More than 250,000 people are estimated to have been killed in Syria's conflict since it started with peaceful anti-government protests in March 2011.