The Islamic State group's loss of territory in Syria and Iraq has been staggering in the past few months. It has lost Mosul, its stronghold in Iraq and is about to lose Raqqa, its de facto capital in Syria.

The U.S.-backed Syrian Democratic Forces (SDF) announced on Wednesday that they have captured 80 percent of Raqqa, while a London based group monitoring the war says that actually 90 percent has been taken from IS.

In a statement, the SDF said it had opened a new front against IS on the northern edge of Raqqa, describing this as "a feature of the final stages of the Euphrates Wrath campaign, which is nearing its end".

The SDF, an alliance of Kurdish and Arab militias, launched their offensive on Islamic State in Raqqa city in June, backed by U.S.-led air strikes and special forces on the ground.

SDF's campaign to capture Raqqa started months ago. Its first stage was to encircle the city. The recapture of the outskirts went relatively fast, but as SDF forces approached the center of the city, the campaign slowed down, mainly because of numerous mines planted by IS.

Reports say that as a result of the fighting and air strikes, hundreds of civilians have died. It is estimated that there are still fewer than 10,000 to as much as 25,000 civilians left in the city.

IS has also lost a lot of ground in Syria's Deir Ezzor province in the northeast, adjacent to the Iraq border.

In the last few weeks, both the U.S> backed SDF and Syrian government forces have pushed back hard against the once powerful, extremist forces of the self-styled caliphate.

The regime forces, backed by Iran and Russia are said to be in control of 70 percent of the city of Deir Ezzor, much like SDF controlling most of Raqqa.

They began their advance from the west, while U.S. backed forces attacked from the north and captured a big swath of territory; almost 200 square miles.

Moscow claimed the U.S. backed forces were impeding the battle, but the U.S. dismissed the charge.

In Iraq, government troops backed by the U.S. led coalition are pushing hard against the last swaths of territory still held by IS. They have taken a number of villages, but it is still not clear when they will be able to recapture all IS held pockets.

Reporting by Reuters and AP