Islamic State has freed 270 people it captured last week during intense fighting with Syrian government forces in the country's east, according to a UK-based activist group.
The Syrian Observatory for Human Rights said that 50 more civilians are still being held.
The freed civilians were released in the village of al-Baghalieh, north of the besieged city of Deir el-Zour.
Over the weekend, IS militants launched a heavy offensive to take the city, which is controlled by the Syrian government deep inside IS territory. More than 100 people were reported to have been killed in the fighting.
Syrian state news agency SANA said government forces have so far managed to repel the advance on Deir el-Zour, with the help of Russian airstrikes.