"This evening, Daesh militants carried out an attack on a bus, which was carrying pilgrims from Iran, near Balad. As a result, seven Iranian pilgrims were injured, along with one Iraqi pilgrim", the paramilitary forces said in a statement, published on their official website late on Sunday.
On Sunday, the bus, which was carrying pilgrims to a Shia mausoleum in Balad, struck a roadside bomb south of the city. It was initially reported that some of the pilgrims were killed.
The 43rd brigade of the Hashd al-Shaabi is carrying out raids in areas neighboring Balad in a bid to seize the Daesh militants who fled the site of the incident promptly after the attack, Sputnik reported.
The AP news agency said the pilgrims were wounded when their bus came under attack by unidentified gunmen.
The officials said late Sunday that the bus carrying 10 pilgrims was north of the capital of Baghdad when gunmen opened fire.
They say the wounded passengers were taken to a hospital, including a woman who was in serious condition.
There has been no claim of responsibility for the attack so far.