ISIS has filmed eight civilians being drowned inside a cage after accusing them of helping the Iraqi government.

The prisoners were forced into a metal cage before being lowered into a pool in the centre of the ISIS-held city of Mosul in Iraq.

They had been accused of 'collaborating with the Iraqi government and Peshmerga forces before the sentence was carried out.

ISIS has filmed eight civilians being drowned inside a cage after accusing them of helping the Iraqi government (file picture)

According to Iraqi News, jihadists are said to have filmed the brutal execution.

It is not the first time the extremists have used the technique to murder their prisoners.

In 2015, a sickening video emerged of five prisoners being locked in a cage in the same city before being drowned in a swimming pool.

In 2015, a sickening video emerged of five prisoners being locked in a cage in the same city before being drowned in a swimming pool (pictured)

The seven-minute film, also captured in Mosul, even featured footage from expensive underwater cameras as the terrified men were thrashing around below the surface.

The latest video comes as Iraqi ground forces continue to move into position around Mosul ahead of a planned operation to retake the militant-held city from ISIS.