An Iraqi military source said 20 members of the radical "Da'ash" group were killed during a bombardment by Iraqi artillery aimed at reinforcements of the extremist organization in the desert of Ana district, 300 km west of Baghdad.

Meanwhile, Iraqi Prime Minister Haider al-Abadi revealed what he discussed with the delegation of the Kurdistan region, which is visiting Baghdad to discuss the referendum scheduled for the 25th of the month for the future independence from Iraq, as A US Army artillery shell killed two US soldiers in northern Iraq on Sunday, a Pentagon official said.

A Pentagon spokesman says the two U.S. soldiers killed Sunday in Iraq were casualties of a U.S. artillery "mishap. The soldiers have been identified as 22-year-old Sgt. Allen L. Stigler Jr. of Arlington, Texas, and 30-year-old Sgt. Roshain E. Brooks of Brooklyn, New York. Both were cannon crew members assigned to 2nd Battalion, 319th Airborne Field Artillery Regiment, 2nd Brigade Combat Team, 82nd Airborne Division.

The Pentagon spokesman, Army Col. Rob Manning, says an Army artillery unit was firing on an Islamic State of Iraq and Syria, or ISIS, mortar position "when a mishap occurred." Manning says there is no indication that ISIS played a role in the deaths. He says he cannot provide other details because the incident is under investigation. Five others suffered injuries that Manning says are not life-threatening.

In the same context, The Joint Operations Command has denied news on beginning of liberation battle of Islamic State-held town of Tal Afar, saying troops still await orders of the army’s command. In a statement on Tuesday, the Joint Operations Command said the plans of Tal Afar liberation operations were set, adding that all Iraqi troops are involved.

“The battle has not started yet. We await commands by the Prime Minister Haidar al-Abadi to declare the zero-hour,” it said indicating arrangement and strikes against IS militants to target its headquarters, weapon stashes and booby-trapping workshops. “The strikes should be based on intelligence information from the Iraqi air force,” according to the statement, which urged media channels to stick to news from the command only.

Defence Ministry spokesman Mohammed al-Khodari was quoted earlier on Tuesday as saying that the ground attack should start after the aerial bombardment campaign. News reports said 12 militants,including prominent leaders, were killed as U.S.-led coalition launched air raids against the group’s locations in the town.

Six powerful blasts occurred as fighter jets targeted explosives workshop, AlSumaria News reported. Tal Afar is one of the important strongholds still held by IS in Nineveh since August 2014, when the militants occupied a third of Iraq to proclaim its self-styled “caliphate.”

On the political side, Prime Minister Haider al-Abadi has told the Kurdistani referendum delegation visiting Baghdad that the Kurdistan Region already acts like a state with an independent economy and army, and that a referendum at this stage is not a “priority,” a member of the delegation told reporters after their meeting on Thursday. 

Saadi Ahmad Pira said that they told Abadi “the objective of this delegation and the decisions made in Kurdistan is a decision for independence.” He appreciated the fact that Abadi was “soft” and “calm” during the meeting, especially as the Kurdistan Region is trying to change the borders of the state he leads. Pira said Abadi’s attitude shows he enjoys “good management” of the issue between Erbil and Baghdad.

 Abadi’s office released a short statement after the meeting, calling the discussions “open and profound” and addressed the necessity to enact proper mechanisms to resolve outstanding problems in a positive climate. Pira quoted Abadi as saying, “If I were a Kurd, I would have been proud to formulate such a demand” to hold the referendum. But the Iraqi leader stated his belief the issue is not a priority since Erbil already acts like a state.