At least 25 Iraqi fighters have been killed repelling a major three-day offensive by the "Islamic State" (ISIS) terrorist group in the region of Haditha in Anbar province, security sources said Tuesday.

"We have given 25 martyrs in 72 hours," a tribal commander, Sheikh Abdallah Atallah, told AFP by phone from Haditha, an area that includes a key dam and has held off ISIS since 2014. "It was one of the biggest offensives we have seen. It came from three directions," he said, adding that dozens were also wounded.