One IS fighter killed every hour in Iraq over past three days

Iraqi forces have killed 75 Islamic State group militants - equivalent to at least one every hour - since launching an offensive against the extremists' last bastion in the country three days ago.

The Baghdad army and the Hashd al-Shaabi paramilitary units on Thursday launched an operation in IS-held towns al-Qaim and Rawa in the western province of Anbar in the Euphrates River valley.

Spokesman for the Iraqi army's Joint Operations Command Brigadier-General Yahya Rasul said 75 militants in al-Qaim district were killed in the 72-hour period, reported the Turkish Anadolu news agency.

On Thursday, Prime Minister Haider al-Abadi's office announced that the army had launched fresh operations aimed at capturing the border towns.

The US-led coalition battling IS said it was "the last big fight" against the militants in Iraq.

Iraqi forces have since taken control of a wide area including villages and essential institutions, according to Rasul.

Earlier, Iraq's defence ministry's Military Information Department also announced the Iraqi army and Hashd al-Shaabi fighters re-captured five villages, al-Khor bridge and al-Qaim railway station in the west of Anbar.

Anbar, Iraq [click to enlarge]

Iraqi jets also hit eight positions which were under the control of IS in al-Qaim and Rawa, leaving many militants dead, as well as destroying an explosives depot and arms depot.

Iraqi forces have retaken more than 90 percent of the territory IS seized in the country in 2014, with the militants now confined to a stretch of the Euphrates Valley adjoining some of the last areas they still hold in Syria.