Surprise attack sees Iraqi forces advance near key Mosul mosque

In February, Iraqi ground forces - backed by the USA -led coalition's air power - began fresh operations aimed at ousting Daesh from western Mosul, the terrorist group's last bastion in northern Iraq.

He said seven soldiers suffered breathing problems and were treated in a nearby field clinic.

Iraqi forces are accusing so-called Islamic State of using chemical weapons in the fight to fully retake the city of Mosul from IS fighters.

There was no comment from the US -led coalition on the report.

The statement said that the forces attacked were part of the massive operation aimed at recapturing the city of Mosul from IS, but did not specify if the attack took place in or outside the city.

The initial operation to liberate Iraq's second largest city began exactly six months ago on October 16.

Mosul west of the Tigris river is smaller but more densely populated, including the narrow streets of the old city.

Various members of the forces, Iraqi and foreign, battling the militants have disagreed in the past on control of territory figures but IS has been losing ground steadily over the past two years.

According to a report published by the Anadolu Agency on Wednesday, the strike targeted several civilian homes in a residential area of Mosul's al-Yarmouk neighborhood, which was recently liberated from Daesh. The U.S. and some other Western nations have blamed the incident on Syrian President Bashar al-Assad and, in response, launched a volley of Tomahawk cruise missiles against a Syrian airbase.

It is not yet known the exact type of chemical used, officials said. Russian President Vladimir Putin and the nation's defense ministry also accused Syrian rebels and ISIS of staging chemical attacks and framing Assad to draw global support.