An estimated 25,000 people have fled escalating violence over the last six months in eastern Syria, the UN said Friday (January 11th).

Much of the unrest has been centred around Hajin in Deir Ezzor province, which had been the last town of note controlled by the "Islamic State of Iraq and Syria" (ISIS) in the area until it was taken in December by the Syrian Democratic Forces (SDF), AFP reported.

The UN High Commissioner for Refugees (UNHCR) said clashes and airstrikes have forced 25,000 people to seek shelter in camps or informal settlements, sometimes after spending several nights in the desert, exposed to harsh weather and without access to food or water.

The agency also warned over "mounting civilian casualties" in the area.

An estimated 2,000 civilians remain trapped in Hajin, where conflict continues, the UN said.

The SDF is currently flushing out the last pockets of land controlled by ISIS in the Euphrates River valley.

The international coalition that is supporting them in the area said Friday that it had begun withdrawing its troops.