HRW said in a report on Wednesday that bombings and shootings across the country were also part of a “campaign of widespread and systematic murder that amounts to crimes against humanity."

The rights group cited the execution-style killing of four Iraqi forces by the al-Qaeda-affiliated Islamic State of Iraq and the Levant (ISIL) near the city of Ramadi in al-Anbar province on January 20.

"These abhorrent killings are the latest in a long list of ISIL atrocities, at a time when civilians in Anbar province are stuck in the fighting," said HRW's Deputy Middle East Director Joe Stork, adding, "Together with the ISIL car bombs and suicide attacks targeting civilians, they are further evidence of crimes against humanity."

A video released at the time showed the special forces being forced to kneel down and then shot in the back of the head by the militants, who claimed responsibility for it later.

Iraqi security forces supported by local tribesmen have been battling the militants in the western province.

The violence in Anbar broke out on December 30, 2013, when the army removed an anti-government protest camp in Ramadi. Authorities said the camp was used as “headquarters for the leadership of al-Qaeda.” The bloodshed later spread to nearby Fallujah.

The Iraqi government has stepped up efforts to boost security across the country over the past few months.

Earlier on Wednesday, at least 34 people were killed by multiple explosions in the capital Baghdad.

Iraqi people have witnessed numerous terrorist attacks since the invasion of Iraq led by the United States in 2003.

NTJ/NJF