Iraqi paramilitary forces say they have captured Hatra, a 2,000-year-old historical site near the northern city of Mosul, where U.S.-backed forces have been battling the Islamic State group for months.

Karim al-Nouri, a spokesman for the state-sanctioned militias, says they captured the UNESCO world heritage site and are around three kilometers (two miles) from a nearby town with the same name, without providing further details.

Iraqi forces often claim to have driven IS from areas that are still far from secure, or that quickly fall back into the militants' hands.

Hatra is believed to have been built in the second or third century B.C. by the Seleucid Empire. IS militants destroyed the site along with other major historical sites in and around Mosul. The extremist group believes antiquities promote idolatry.