Iraq's powerful Shia militias on Saturday announced that they had launched an offensive aimed at capturing the town of Tel Afar and other areas west of Mosul from Daesh extremists.
Meanwhile, the head of the Iraqi police said his forces had captured Shura, a key town some 35 kilometres south of Mosul, from Daesh.
The Shia militias and military and police units, advancing from the south, had captured seven villages by midday, according to the head of military operations for Nineveh province, General Najm al-Jabouri.
The operations were taking place on the orders of the Iraqi military command but without any coordination with a US-led coalition that has provided air support to government forces in the Mosul campaign, sources in the pro-government militias said.
The participation of the Shia militias in the battle for Sunni-majority Mosul, the only major Iraqi city still held by Daesh, has been controversial.
Local residents and politicians accused the militias of abuses, including the killing of a number of civilians, during operations to recapture the western city of Fallujah from Islamic State earlier this year.
Analysts say that prior to the capture of Mosul in 2014, a major factor in Daesh's rise was that the country's Sunni minority felt victimized by the Shiite-dominated government and security forces under former prime minister Nuri al-Maliki.
Al-Maliki was forced to step down in 2014 after Daesh seized Mosul and other Sunni-populated areas of northern and western Iraq in a lightning offensive.
Iraqi Prime Minister Haider al-Abadi, a conciliatory figure despite his Shia Islamist background, has said only the Iraqi army and police will enter Mosul itself.
The militias say their role will be to capture areas west of the city, including Tel Afar, and cut off Daesh forces in the Mosul area from its units elsewhere in Iraq and in eastern Syria.
Tel Afar's largely Turkmen population may cause further tensions between Iraq and Turkey, whose president, Recep Tayyip Erdogan, has repeatedly insisted that his forces should play a part in the campaign for Mosul and warned against the Shia militias.
Hours after the move towards Tel Afar was announced, the head of the Iraqi federal police said his forces had captured the town of Shura, some 35 kilometres south of Mosul.
Iraqi forces have had to make up more ground south of Mosul than on the eastern and northern fronts, where Kurdish Peshmerga and elite Iraqi army counter-terrorism forces have advanced close to the city.
Security forces on the southern front will need to make rapid progress through entrenched Daesh defences "lest the axes [of the offensive] grow out of sync," the US-based Institute for the Study of War said in an analysis published on Friday.
In Baghdad, meanwhile, seven people were killed when a suicide bomber blew himself up during a Shia procession in the west of the city, eyewitnesses said.
Daesh has frequently carried out deadly bomb attacks on Shia religious ceremonies and busy locations in mainly Shia neighbourhoods.
By Kadham al-Attabi and Pol O Gradaigh
© 2019 dpa GmbH