2nd gas attack on Iraq troops in as many days

Iraqi Federal Police fires his rifle at ISIS militants' positions at Bab al Jadid district in the old city of Mosul, Iraq, March 26, 2017.

Battles are now most intense around Mosul's densely populated and narrowly structured Old City district, where police forces cautiously approach the grand mosque where IS supreme leader Abu Bakr al-Baghdadi declared the establishment of the group's rule.

US -backed Iraqi forces are now battling self-proclaimed Islamic State militants in the more densely-populated western half of Mosul.

The brutal fighting has taken a massive toll on the civilian population.

But "the final neighbourhoods will be the most hard to recapture, especially the Old City and the remaining neighbourhoods in northwestern Mosul", Martin said.

Brigadier General Rick Uribe, a senior coalition commander, lamented that they find it hard to negotiate alleyways and narrow streets.

"We're doing everything we can but this has been a long battle and the assault on the old city hasn't started", Grande warned, pointing out that the battles in the western side of Mosul is very different than in the east.

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The fighting has killed several thousands among civilians and fighters on both sides, according to aid organisations.

The coalition has said it "probably" played a role in civilian casualties in Mosul, while residents have been caught up in fighting between Iraqi forces and IS, and the jihadists are intentionally attacking civilians in the city.

As many as 500,000 civilians could remain in parts of western Mosul under Daesh jihadist group control, OCHA estimates.

"Mosul has pushed us to our operational limits", Grande said.

However, the western part of Mosul, with its narrow streets and heavily populated neighborhoods, appears to be a bigger challenge to the Iraqi forces.

He said that around 30 people had been killed in the attack.

  • Adam Floyd