At least 30 civilians were killed Thursday during a series of airstrikes on two areas of Syria controlled by Daesh extremist militia, the Syrian Observatory for Human Rights reported.
Twenty-three were killed in a bombardment by suspected U.S.-led coalition jets on the village of al-Matab on the eastern outskirts of al-Raqqa, which is Daesh's de-facto capital in Syria, the monitoring group added.
A further seven civilians died when aircraft - believed to be Russian- carried out some 25 strikes Thursday on the Daesh-held area of al-Mayadeen east of Deir al-Zour, the Observatory said.
The strikes hit a local school, a bakery and a municipality building, leaving at least 70 injured, the watchdog added.
Al-Matab village lies near a key road linking al-Raqqa in northeastern Syria with the city of Deir al-Zour in the east. The fatalities there included eight children.
"Most of those killed were from one family," Observatory head Rami Abdel-Rahman said.
At least 890 civilians have been killed in a U.S.-led campaign targeting militants that began fighting in war-torn Syria in September 2014, according to the observatory.
A Kurdish-led alliance, backed by the United States, began a major offensive in November to recapture al-Raqqa, which has been under Daesh rule since 2014.
Daesh controls half of Deir al-Zour as well as most of the surrounding province of the same name.
On January 14, Daesh insurgents started a massive attack on regime-held areas in Deir al-Zour.
In recent months, the terror group has been the target of multiple campaigns in Syria.
Regime forces, backed by allied Russian jets, Thursday entered the al-Jarah military airport on the eastern edge of the northern province of Aleppo after Daesh fighters had fled the facility to al-Raqqa, the Observatory said.
In recent weeks, government forces have wrested back several villages in Aleppo from Daesh as part of a Russia-backed onslaught.
Earlier this week, the Syrian Democratic Forces - an alliance of Kurds and Arabs that is currently encircling al-Raqqa - cut off a major road leading east of al-Jazzrah region on the northwestern outskirts of al-Raqqa.
The route connects al-Raqqa with Deir al-Zour province.
In recent months, Daesh has suffered military setbacks and lost territory in Syria and neighboring Iraq.