Iraqi forces are just a street away from storming Mosul's old quarter in what many believe will be the defining phase for the battle for Iraq's second city.

Sky News Chief Correspondent Stuart Ramsay joined Iraq's emergency response division near the front line of the fierce battle.

Here he describes accompanying the soldiers on a rare night-time mission to liberate another neighbourhood on the way to the old quarter:

Into the heart of Islamic State-controlled west Mosul, Iraqi forces launch a night raid on foot and by Humvee supported by helicopter gunships and artillery.

This is brand new for most of the Iraqi soldiers: they aren't keen and they don't have night-vision goggles, but commanders are convinced that 24-hour attacks will pay dividends despite the increase in danger.


Image: The mission start in the middle of the night

We joined them through the night and into the morning as the operation raged to take the last few streets before the start of the old city.

It was an operation punctuated throughout by enormous missiles, deadly car bombs and continuous firefights.

Just a couple of streets from the myriad of alleys that make up the old city is the front line.

Image: The raid runs through to the early morning

The fighting here has been horrendous and the damage catastrophic, with enormous buildings and whole streets flattened. The east of the city was largely spared this.

Armoured diggers cleared away the rubble to build barriers to protect the soldiers from suicide attacks by car and to make the passage easier for their vehicles.

The area is taken but not held. Snipers are a constant and everyone scuttles across main roads to the safety of vehicles and buildings.

Image: Diggers clear the way so barriers can be built to protect the soldiers from suicide attacks

We race to a building that marks the start of the old city and come across resting soldiers who say that there have been four enormous car bombs and that IS fighters are dug in and determined.

On the roof, an Iraqi sniper team crouches beneath the parapet. They are under fire. Soon the whole building, then the entire area is.

A powerful explosion and incoming rounds echo around the building's stairwell. From a window, soldiers look down at the smoke from a mortar that landed where we had taken cover only minutes before.

The Iraqi forces take cover. The streets empty and the soldiers accompanying us disappear as it is clear that IS fighters are closing in on our position.

We make a dash to the assumed safety of a building, halfway to the relative safety of our Humvee. But a round spanks off a metal hoarding and while soldiers sprint past us we do the same, risking the crossfire.

Image: Snipers are a constant danger in the open

There is considerable confusion, with soldiers running in all directions trying to find the Islamic State firing point; they soon realise the attack is coming from an alleyway and return fire as a bulldozer attempts to seal it.

But another sniper opens up from a different direction.

This is the chaos of this hard conflict.

The west of Mosul really is proving to be the Islamic State stronghold everyone feared, and as I write the fighting continues.

There hasn't been any let up of any description since I arrived here - that is 48 hours and counting.