Three Islamic State fighters were killed and five more were injured Sunday by an ambush of stampeding wild boars in northern Iraq, according to local leaders.

Sheikh Anwar al-Assi, a chief of the local Ubaid tribe and supervisor of anti-ISIS forces in the area, told the Times of London that the militants were setting up an ambush on the edge of a field about 50 miles southwest of Kirkuk. The group was planning to attack a band of local tribesmen who had fled from the ISIS-controlled town of Hawija, which the jihadists seized in mid-2014.

Three militants were reportedly killed and five more were injured. Al-Assi said the group of eight likely disturbed a herd of wild pigs, which inhabit the area and apparently mauled the fighters.

According to Al-Assi, the militants had summarily executed 25 people fleeing the Islamic State's territory in the three days before the boar attack.

Hawija is east of the road from Mosul to Baghdad, by the oil-rich Kirkuk region.

An effort backed by U.S. troops to drive ISIS out of Mosul began in October, with the eastern half of the city liberated by January. The Iraqi military claimed on Tuesday to have taken back the al-Tanek neighborhood, the largest in Mosul's western half.

Hunting, eating, and trading wild boar is forbidden under Islamic law.