BEIRUT: Russian and regime air strikes killed 47 people, most of them civilians, and wounded dozens more on Saturday in a jihadist-held town in eastern Syria, a monitor said.

The Syrian Observatory for Human Rights said the raids hit the town of Al-Quriyah, controlled by the Islamic State group in Syria’s oil-rich Deir Ezzor province.

Observatory head Rami Abdel Rahman said 31 civilians were identified among those killed, but that it was not immediately clear whether the 16 others were civilians or IS fighters.

"IS fighters have now set up a security perimeter around the residential area, where the town’s mosque is located," said Abdel Rahman.

The Britain-based monitor -- which relies on a network of sources inside Syria for its information -- says it determines what planes carried out raids according to their type, location, flight patterns and the munitions involved.

Russian warplanes have been carrying out an air war in support of President Bashar al-Assad since September 2015.

More than 280,000 people have been killed since Syria’s conflict erupted in March 2011, after a widespread protest movement evolved into a complex, multi-front war that has drawn in global powers.

Across the frontier in the Iraqi city of Fallujah, security forces were poised to assault Jolan, the last neighbourhood still held by IS.

Tens of thousands of people fled the fighting, with many camped out in the open in the summer heat.

"Dozens of families are still without tents or any form of shelter inside the camps, living in miserable conditions. The majority are elderly people, women and children," said the Norwegian Refugee Council.

The SDF launched its offensive to take Manbij on May 31, driving across the Euphrates River from the east with military advice from some 200 US special forces troops.

IS has thrown large numbers of fighters into the battle, losing 463, according to the Observatory. The SDF has lost at least 89.

The jihadists have taken as many as 1,000 Kurdish civilians hostage in areas under their control west of Manbij, according to the Observatory.

Manbij lies in the eastern plains of Aleppo province, which has become a battleground between an array of competing armed groups, including al-Qaeda, non-jihadist rebels and government forces, as well as the SDF and IS.

Aleppo was once the country’s commercial hub but now lies divided between government forces in the west and rebels in the east.

A two-day freeze on fighting brokered by Moscow and Washington this month expired without renewal.

On Saturday, Russian and Syrian warplanes pounded rebel-held areas in and around the city in support of a regime offensive on the rebels’ sole remaining supply route, the Observatory said.

The Castello Road has been repeatedly hit by air strikes but residents said the bombing had intensified in recent days.