Updated

Russia says nearly 18,000 people have fled eastern Aleppo in the last 24 hours in a "constant stream" as Syrian government forces close in on the last pocket of opposition control in the northern city.

Russian Defense Ministry spokesman Maj. Gen. Igor Konashenkov said Saturday that Syrian troops have suspended their offensive to allow for the evacuation of civilians, but the activist-run Syrian Observatory for Human Rights says heavy clashes are still underway.

The Russian military's Center for Reconciliation in Syria says 17,971 civilians, including 7,542 children, have left rebel-controlled Aleppo districts in the last 24 hours.

Backed by Russia and other allies, Syrian President Bashar Assad's forces have driven the rebels from nearly all of eastern Aleppo, which was captured by the opposition in 2012.