Iraqi special forces neared the eastern city limits of Mosul on Monday, tightening the noose as the offensive to retake the Islamic State group stronghold entered its third week.

Forces from the elite Counter-Terrorism Service (CTS) faced mortar fire as they pushed from the Christian town of Bartalla towards Mosul's eastern suburbs, AFP correspondents at the front said.

As an aircraft struck a suspected IS mortar position in the distance, a convoy of Humvees sprayed gunfire across the arid plain at an industrial area held by jihadists.

Lieutenant Colonel Muntadhar al-Shimmari said CTS had recaptured Bazwaya, one of two IS-held villages that had been standing between Iraqi forces and the eastern edges of Mosul.

"Tonight, if everything is secured, we will be 700 metres (yards) from Mosul," Shimmari said.

CTS forces had entered the second village, Gogjali, and were battling to retake it, Staff Lieutenant General Abdelwahab al-Saadi, a senior CTS commander, told AFP by telephone.

He denied reports that Iraqi forces had entered the Al-Karama area -- about 2.5 kilometres (1.5 miles) from Gogjali -- inside Mosul itself.

Backed by air and ground support from a US-led coalition, tens of thousands of Iraqi fighters are converging on Mosul on different fronts, in the country's biggest military operation in years.

On the northern and eastern sides of Mosul, the extremist group's last major bastion in Iraq, peshmerga forces from the autonomous Kurdish region recently took several villages and consolidated their positions.

- New western front -

To the south of the city, federal forces, backed by coalition artillery units stationed in the main staging base of Qayyarah, have been pushing north.

They have the most ground to cover and are still some distance from the southern limits of Mosul.

Paramilitary forces from the Hashed al-Shaabi (Popular Mobilisation), an umbrella organisation dominated by Iran-backed Shiite militia, opened another front over the weekend.

They are not directly headed for Mosul, instead setting their sights on the town of Tal Afar to the west, with the aim of retaking it and cutting supply lines between Mosul and the Syrian border.

Their leadership says publicly that they do not intend to enter Mosul, which has an overwhelmingly Sunni population, but commanders on the ground say they want to fight inside the city.

The initial shaping phase of the operation, during which dozens of villages and several towns have already been retaken from IS, is still under way.

Once the initial phase is over, Iraqi forces are expected to besiege Mosul, attempt to open safe corridors for the million-plus civilians still believed to live there, and breach the city to take on die-hard jihadists in street battles.

Humanitarian organisations have been fighting against the clock to build up the capacity to handle an expected exodus from the city.

The United Nations says up to a million people could be displaced in the coming weeks.

More than 17,000 people have already fled their homes since the start of the operation and the Norwegian Refugee Council said there were currently only 55,000 more places available in camps.

- Post-'caliphate' life -

In the dozens of villages and towns scattered over territory retaken from IS over the past two weeks, civilians were very slowly returning to a life free from the "caliphate" IS declared in Mosul in 2014.

Qaraqosh, which was previously Iraq's largest Christian, saw its first mass in more than two years on Sunday.

"After two years and three months in exile, I just celebrated the Eucharist in the cathedral of the Immaculate Conception the Islamic State wanted to destroy," Yohanna Petros Mouche, the Syriac Catholic Archbishop of Mosul, said.

Most retaken areas were far from being habitable however, with months of mine clearing and reconstruction needed before the bulk of the original population can return.

IS has been losing ground steadily in Iraq since 2015 and the outcome of the Mosul battle is in little doubt, but commanders have warned it could last months.

The loss of Mosul, where jihadist supremo Abu Bakr al-Baghdadi declared his Islamic "state" in June 2014, could end the days of IS as a land-holding force in Iraq.

That would leave the Syrian city of Raqa as the group's only major hub. The US-led coalition and its allies on the ground have pledged to attack it soon.

Turkey says Raqa operation should start after Mosul operation ends
Ankara (AFP) Oct 31, 2016 - Deputy Prime Minister Numan Kurtulmus said Monday Turkey wants the drive to oust Islamic State jihadists from the Syrian city of Raqa to begin after operations in Iraq's Mosul and a Turkish-backed mission in northern Syria are over.

"It would be right, militarily and strategically, to conduct this Raqa operation after the Mosul operation and Turkey's Euphrates Shield operation have ended," he told reporters in Ankara.

Last week US Defence Secretary Ashton Carter said operations for the "isolation" of Raqa, the de-facto capital of IS' self-declared caliphate, should begin in conjunction with the assault on Mosul.

An offensive by Iraqi and Kurdish peshmerga forces to free Mosul, Iraq's second biggest city, began in mid-October with air support from the US-led coalition.

Meanwhile Turkey is continuing with an operation called Euphrates Shield, launched on August 24, in which it is supporting opposition fighters in northern Syria with tanks and air strikes.

The Ankara-backed fighters comprise various brigades rather than one organised force, according to experts.

So far, the rebels have captured the IS stronghold of Jarabulus and retaken the symbolically important town of Dabiq.

Turkish President Recep Tayyip Erdogan said last week that the rebels would target Raqa after advancing towards the city of Al Bab in northern Syria and taking Manbij, recently captured by Syrian Kurdish YPG militia.

Euphrates Shield has two main goals: to clear IS elements from the Turkish-Syrian border and halt the westward advance of the YPG.

Last week Ankara conducted air strikes against People's Protection Units (YPG) positions to stop their advance towards Al Bab, Turkish media said.

Ankara views the YPG as linked to the outlawed Kurdistan Workers' Party (PKK), which has been waging an insurgency inside Turkey since 1984.