Hossain Hajem, the deputy governor of Mosul in Nineveh province, made the announcement on Sunday.
He added that at least 17 civilians, including women and children, suffered respiratory problems after Daesh shelled Osija village, located on the southern outskirts of Mosul.
Hajem said it was believed, after initial inspection, that the shells contained chlorine gas, a choking agent banned under the 1997 Chemical Weapons Convention.
The official added that the terrorist group had shelled several other villages on the southern outskirts of the provincial capital over the past 24 hours, leaving at least three people dead and four others injured.
It is not the first time Daesh has used chemical weapons against civilians.
On February 18, Kurdish authorities reported a similar attack launched by Daesh on the city of Sinjar, where at least 30 Peshmerga fighters were injured.
In addition to Iraq, the terrorist group has frequently used poisonous agents against people in Syria.
On April 7, nearly two dozen people were killed and over 100 others injured in a chemical attack by Daesh against members of the Kurdish People’s Protection Units (YPG) in Aleppo.
According to a report by the Syrian-American Medical Society, Daesh has carried out more than 160 attacks involving “poisonous or asphyxiating agents, such as sarin, chlorine, and mustard gas” since the beginning of the conflict in Syria in 2011. Over 1,490 people have been killed in the chemical attacks.