The anti-terror operation that Iraqi security forces are facing is huge. It will also be a massive test of their abilities.

Not only are they having to fight a war but they are also having to provide security and win "hearts and minds" in a city where the civilian population has been or still is under constant fire.

They are of course not a foreign army but when it comes to Mosul they might just as well be.

Baghdad's rule was never popular - even before Islamic State's shockingly violent rise to power.

It may just be that the brutal fight for the city is the easy bit.


Keeping the jihadists from returning and finding terrorists determined to launch an insurgency to undermine security provisions will be much harder.

We joined a SWAT team on the hunt for an IS explosives expert called Ali Khattar.

The neighbourhood in east Mosul - which is now under the control of Iraqi forces - was home to many IS fighters.

Image: A suspected militant is blindfolded by Iraqi troops

At the house where he was staying the suspect was dragged on to the street. Warning shots were fired as he was interrogated.

The SWAT team argued with his female relatives as they and he protested his innocence.

After 30 minutes it turned out that the man they had roughed up and threatened violently was an entirely different person.

They moved on to another house and continued the search but the "raid" demonstrates just how hard it is to find dangerous IS operatives that have gone to ground.

What is also obvious is the more they get it wrong and the more allegations there are of abuses of power the greater the benefit it is to the extremists.

Rough justice is an excellent recruiting sergeant. And so many men are being rounded up the security forces are finding it hard to process them all.

The urgency of this anti-terror operation is evident.

In the past few months there have been several suicide bomb attacks in eastern Mosul.

The Iraqi army is now guarding the streets but people are not reassured.

Residents of one district told us they were scared IS would return.

We were told of one incident in which an IS militant was caught with a car full of weapons and explosives.

He was arrested but soon surfaced again in the neighbourhood after paying off his captors.

The hunt for the group's rank and file insurgents and delivering justice to them will be the biggest test for the Iraqi security forces when the "Caliphate" finally falls in Iraq.

However, providing security without alienating the local population will not be easy.

:: Watch a special programme, The Battle For Mosul, at 7pm on Monday on Sky News.