BAGHDAD — Iraqi paramilitary forces said Wednesday that 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. The media arm of the state-sanctioned force made up mainly of Shiite militias broadcast images of the site Wednesday, showing what appeared to be the ancient ruins in the distance as militia vehicles drove through open desert. Karim al-Nouri, a spokesman for the paramilitary forces, told state TV they captured the UNESCO world heritage site and were around 2 miles from a nearby town with the same name, without providing further details. The extremist group believes antiquities promote idolatry, though it is also believed to sell artifacts on the black market to fund its operations. In April 2015, Islamic State released a video showing the extremists smashing sledgehammers into Hatra’s walls and firing assault rifles at priceless statues. The militants’ basic strategy appears to be to focus much of their efforts on blunting the counterterrorism service’s attack, calculating that if they can stymie Iraq’s most experienced fighting force, the Iraqi government’s broader offensive will bog down.