Iranian-backed Iraqi Shiite paramilitary groups said they started an offensive on Saturday against Daesh positions in the town of Tal Afar west of Mosul, assisting in a campaign to take back the city, amid clear and repeated warnings from Turkey that their assault into the town could trigger an intervention.
The operation will target Tal Afar, an Daesh-held area close to Turkey where a sizeable ethnic Turkmen population lives, which could cause concern in Ankara. Turkish officials repeatedly stated that the inclusion of Shiite militia and PKK terrorists - which hold positions in the predominantly Yazidi town of Sinjar located some 50 kilometers west of Tal Afar - in operations in and around Mosul could trigger ethnic and secterian conflicts in the region, adding that Turkey may intervene if Turkmen population is targeted in Tal Afar. The town is located some 80 kilometers south of Turkey's borders.
Earlier announcements by the militias, collectively known as Hashdi Shaabi or Popular Mobilization Forces (PMF), on advancing toward Mosul has drawn warnings from human rights groups concerned about sectarian violence in the mainly Sunni province. Shiites make up a majority in Iraq but Sunnis are predominant in the north and the west.
The PMF said it had started moving early on Saturday toward Tal Afar from positions south of Mosul, Daesh's last major city stronghold in Iraq.
"The wounded city of Tal Afar (is among) the cities to be liberated," said a statement on the PMF's website.
"The operation aims to cut supplies between Mosul and Raqqa and tighten the siege of Daesh in Mosul and liberate Tal Afar," PMF spokesman Ahmed al-Assadi told AFP, adding that the operation aimed to retake the towns of Hatra and Tal Abta as well as Tal Afar.
The operation could bring the fighting perilously close to the ancient city of Hatra, located northeast of the town of the same name, a UNESCO world heritage site that has already been vandalized by Daesh.
The involvement of Shiite militias in the Mosul operation has been a source of contention, although some of the PMF's top commanders insist they do not plan to enter the largely Sunni city.
Iraqi Kurds and Sunni Arab politicians have opposed their involvement, as has Turkey, which has a military presence at the Bashiqa camp located east of Mosul. The presence of Turkish troops in Bashiqa, which trains local Sunni forces and Kurdish peshmerga, led to a diplomatic spat between Ankara and Baghdad, as the latter claimed breach of its sovereignty despite previous invitations by Iraqi officials.
The PMF officially reports to the Shiite-led government of Prime Minister Haider al-Abadi who on Oct. 17 announced the start of an offensive targeting Mosul, Iraq's second-largest city, with the backing of a U.S-led coalition.
The PMF was formed in 2014 to help push back Daesh's sweeping advance through northern and western provinces.
Amnesty International says that in previous campaigns, the Shiite militias have committed "serious human rights violations, including war crimes" against civilians fleeing Daesh-held territory.
The U.N in July said it had a list of more than 640 Sunni Muslim men and boys reportedly abducted by a Shiite militia in Falluja, a former militant stronghold west of Baghdad, and a list of about 50 others who were summarily executed or tortured to death.
The government and the PMF say a limited number of violations have occurred and that they were investigated but they deny that abuses were widespread and systematic.