Iraqi forces on Thursday recaptured two more neighbourhoods in west Mosul, tightening the noose around Daesh holed up in the Old City, commanders said.
Iraqi forces retook the side of the city that lies east of the Tigris river in January and launched a push on remaining terrorists in western Mosul.
"The forces completed the liberation of Al-Thawra neighbourhood," Sabah al-Noman, spokesman for the elite Counter-Terrorism Service said.
The neighbourhood which lies just west of the Old City had been retaken from Daesh, said an officer with federal police forces.
The Joint Operations Command said the Nasr neighbourhood was also retaken on Thursday.
The head of Iraq's federal police, Raed Shakir Jawdat, said in a statement that Iraqi forces had killed a senior Daesh operative, who had been in charge of chemical weapons for the group in Mosul, in a guided missile strike in the Zanjili neighbourhood.
A US official said on Wednesday that Daesh targeted Iraqi forces working alongside the US and Australian military advisers, using a low-level chemical agent in west Mosul.
But nobody died in the attack, said Major General Joseph Martin.
Iraqi forces in mid-October last year launched a huge operation, their largest in years, to retake Mosul, the country's second largest city.
On the west bank, Iraqi forces control southern neighbourhoods and are slowly surrounding the Old City while an estimated 400,000 civilians are believed to still be there.
Iraqi forces on Thursday launched a fresh push against Daesh-held villages, as part of a months-old operation to retake areas along the Euphrates in western Anbar province.
According to an Iraqi military spokesman, Daesh only control seven percent of Iraq, down from the 40 percent of the national territory over which they took over three years ago.
The only two other significant towns Daesh still holds are Hawija and Tal Afar.
Daesh also control territory in remote areas of western Iraq, near the Syrian border.
A senior officer said the operation forces included the army, local tribal fighters and military advisers from the US-led coalition assisting Iraq in the anti-Daesh war.
The loss of Mosul would be a death blow to the so-called "caliphate" Daesh proclaimed after capturing the city in a massive offensive in June 2014.