An Iraqi federal police commando leader said at least six "Islamic State" (IS) suicide car bombs had failed to deter Iraqi troops from advancing toward Mosul's old western city center.

The cars fitted with explosives had been destroyed before reaching troops, said Major General Haider al-Maturi. Snipers had also tried to deter Iraqi forces as they approached from Mosul's south.

US-trained units were also approaching from the southwest, said joint command spokesman, Brigadier General Yahya Rasool.

Police colonel Emad al-Bayati told the Deutsche Presse-Agentur news agency that troops had taken control of several police stations and military sites.

Mosul's eastern quarters were captured in January. The push for western Mosul began on February 19 with the retaking of the city's airport, but was delayed earlier this week due to bad weather.

Thick smoke

Lebanon-based Al-Mayadeen television showed thick black smoke filling the sky over western Mosul on Sunday amid a heavy exchange of gunfire.

Anticipating the battle, 45,714 individuals or 7,619 families fled western Mosul over the past two weeks, the International Organization for Migration (IOM) reported on Sunday.

The IOM said 206,520 people were currently displaced, less than the exodus of a million anticipated. Some had fled but later returned to their homes, the organization added.

On Saturday, the UN's humanitarian coordinator in Iraq, Lise Grande, said the alleged use by IS of chemical weapons earlier this week in an eastern district was "horrible."

Ten patients from Mosul were in a stable condition, said Hussein Qader, the deputy director of a hospital in Irbil where victims, including children, are being treated.

Mosul, Iraq's second-largest city, lies in a swathe of territory west and north of Iraq's capital, Baghdad, and was overrun by IS in 2014.

At the time, the area was declared by IS leader Abu Bakr al-Baghdadi to be the Iraqi wing of a caliphate spanning adjourning regions of Iraq and Syria.

In recent months, the militants have also lost some territory in neighboring Syria.

On Saturday, the Pentagon said coalition air strikes in Iraq and Syria between November and January had killed 19 civilians. Independent monitoring organizations typically put civilian casualties much higher.

ipj/jlw (AFP, dpa, Reuters)