The capture of the base could be a significant development in the campaign to recapture Mosul, Islamic State's de facto capital since its forces swept through Iraq in 2014 and set up a self-declared caliphate in a swathe of Syria and northern Iraq.
The Tal Afar base also offers the mainly Shia forces a launchpad for operations against Islamic State (ISIS / Daesh / ISIL) targets inside Syria, and highlights the potential for the Mosul operation to reshape strategic power across northern Iraq.
Popular Mobilisation, known locally by its Arabic name Hashid Shaabi, showed black plumes of smoke rising from targets bombed in the vicinity of the airbase during heavy fighting, as car bombs used by Islamic State to hinder the advance of Shia fighters we hit causing huge explosions.
While the Shia coalition is fighting Islamic State west of Mosul, Iraqi army and police units are trying to advance from the other sides of the city, backed by Kurdish peshmerga fighters deployed in the north and the east.
Iraqi counter-terrorism forces breached Islamic State (ISIS / Daesh / ISIL) defenses in east Mosul two weeks ago but have faced resistance from the militants, who have fought back with suicide car bombs, snipers and waves of counter-attacks.
The campaign to retake Mosul that began on October 17 with air and ground support from a US-led coalition, is the biggest military operation in Iraq in more than a decade of turmoil unleashed by the 2003 invasion that toppled Saddam Hussein.
Hashid Shaabi, has said it plans to use Tal Afar base to take the battle against Islamic State into Syria, fighting on the side of President Bashar al-Assad.
Popular Mobilisation has said it plans to use Tal Afar base to take the battle against Islamic State into Syria, fighting on the side of President Bashar al-Assad.
Popular Mobilisation's advance towards Tal Afar, which had a mixed population of mainly Shia and Sunni Turkmen before Islamic State (ISIS / Daesh / ISIL) captured it in 2014, has raised the prospect of sectarian strife and alarmed neighboring Turkey.
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