Islamic State (IS) extremists have unleashed a wave of suicide attacks targeting the Iraqi army in western Anbar province, killing at least 17 troops.

It is a major blow to government efforts to dislodge the militants from the sprawling Sunni heartland, an Iraqi military spokesman said.

The attacks came just hours after the Iraqi government announced the start of a wide-scale operation to recapture areas under the control of the IS group in Anbar.

Brigadier General Saad Maan Ibrahim, the spokesman for the Joint Military Command, said that the attacks took place outside the IS-held city of Fallujah.

The militants struck near a water control station and a lock system on a canal between Lake Tharthar and the Euphrates River where army forces have been deployed for the Anbar offensive, he said.

Brig Gen Ibrahim added that the extremists used the cover of a sandstorm that engulfed most of Iraq to launch the deadly wave of bombings.

He said it was not clear how many suicide attackers were involved in the bombings but they hit the military from multiple directions.