Footage has emerged of Taliban fighters mocking American troops by exercising in the gym at an abandoned US military base in Afghanistan.

It comes as the terror group unleashes a reign of terror after seizing control of a third of the country since US troops deserted in June.

The clip begins with one man playing around with two ropes and shows him swinging from side to side.

The cameraman can be heard laughing while recording his comrades play around on the gym equipment.

Then the camera moves to a punching bag where the cameraman briefly tries his hand at boxing the bag before letting his associate take over.

The group takes it in turns to try and tackle the punchbag, flailing and kicking at it to little avail.

Meanwhile, terrified Afghanis have begun fleeing the Taliban as the militants sweep across the country.

Below is the video: