A veteran fighter known as 'the sheikh of snipers' has been killed in Iraq's battle to retake the town of Hawija from the Islamic State group, his paramilitary force announced on Saturday.

Abu Tahsin al-Salhi, who took part in conflicts dating back to the 1973 Arab-Israeli war and said he had gunned down at least 321 ISIS jihadists, died on Friday, Daily Mail reported.

The 63-year-old, who boasted of at least four hits a day, was killed as he advanced on Hawija in northwest Iraq, said Ahmad al-Assadi, spokesman for the Hashed al-Shaabi alliance mostly of Shiite militias fighting alongside government forces against the last jihadist bastions.