Iraqi Shi’ite militias say they have driven ISIL fighters from an air base west of Mosul.
The victory, if confirmed, would threaten the Sunni group’s supply route from Syria to its last major stronghold in Iraq.
What is the strategic significance?
If confirmed, the capture could be a significant development in the campaign to recapture Mosul, ISIL’s de facto capital.
The group’s forces swept through Iraq in 2014 and set up a self-declared caliphate in a swathe of Syria and northern Iraq.
The town lies around 60 kilometres west of Mosul on the main road to Syria.
Its seizure could also alarm Turkey, which is wary of Iraqi Shi’ite involvement in the civil war in Syria.
The Mosul campaign
While the Shi’ite coalition is fighting ISIL west of Mosul, regular army and police units are trying to advance from the other sides.
They are backed by Kurdish Peshmerga fighters deployed in the north and the east.
Iraqi counter-terrorism forces breached ISIL defences in eastern Mosul two weeks ago.
However, they have faced resistance from militants who have fought back with suicide car bombs, snipers and waves of counter-attacks.
The government forces have been fighting in a dozen of the estimated 60 neighbourhoods on the eastern part of Mosul, which is divided by the Tigris River.
They have yet to enter the town from the northern and southern sides.
When did the campaign start?
On October the 17th.
Using air and ground support from a US-led coalition, it is the biggest military operation in Iraq in more than a decade, since the 2003 invasion that toppled Saddam Hussein.
A springboard for Syria?
Popular mobilisation, known locally by its Arabic name, Hashid Shaabi, says it plans to use the Tal Afar air base to take the battle against ISIL into Syria.
The group will fight on the side of President Bashar al-Assad, an ally of Iran.
Although it officially reports to Iraqi Prime Minister Haider al-Abadi, it is mainly trained and equipped by Iran.
The prospect of sectarian strife
The advance towards Tal Afar has raised the prospect of sectarian strife.
It has also alarmed neighbouring Turkey.
The town had a mixed population of mainly Shi’ite and Sunni Turkmen before ISIL captured it in 2014.
Turkish President Recep Tayyip Erdogan said last month that Turkey is reinforcing its troops on the border with Iraq and will respond if the militias “cause terror” in Tal Afar.
Iraq has sought to calm fears that the operation to recapture Tal Afar would ignite sectarian tension or escalate problems with Turkey.
Haider al-Abadi has said the attacking force entering the town will reflect its religious and ethnic make-up.
The Nineveh region surrounding Mosul is a mosaic of ethnic and religious communities, including Arabs, Turkmen, Kurds, Yazidis, Christians, Sunnis and Shi’ites.
Sunni Arabs, however, are by far the overwhelming majority.
Mosul in numbers
- 5-6,000 ISIL fighters
- 100,000 Iraqi coalition fighters
No official casualty figures
57,000 displaced by fighting – UN
1,000,000 reportedly being used as human shields
The desecration of Nimrud
Iraqi experts are setting up field teams to assess the damage to the historic remains in Nimrud.
ISIL have been driven out of the town but are said to have destroyed as much as they could beore they left.
The worst of the damage is said to have been caused in the last two months as the Iraqi army advanced.
This seems to have been confirmed by evidence from satellite images.
What they are saying
“The airport of Tal Afar has been liberated,” – Yusif al-Kallabi, spokesman for Popular Mobilisation, a coalition of mainly Iranian-backed militias.
“Tal Afar will be the starting block for the liberation of all the area to the Syrian border and beyond the Syrian border,” – Hadi al-Amiri, head of the Badr Organisation, the largest component in the Popular Mobilisation.