A renegade sniper has been striking fear into the hearts of ISIS thugs in Mosul — picking them off one-by-one, reports claim. The mysterious marksman — dubbed the “Sniper of Mosul” — is believed to be behind shootings in four separate neighborhoods in Iraq’s second largest city. But officials think the resistance fighter could be receiving help from other gunmen, according to the Daily Star. The sniper has been hunting down militants in broad daylight, with the most recent hit unfolding during a public beheading. Iraqi media outlets on Monday reported the shooter had killed an ISIS executioner just seconds before he could behead a local teen who was accused of supporting resistance movements within Mosul. His bullet struck the terror thug just as he was taking aim at the boy’s neck, sources said. The attack prompted the terrorists to frantically open fire and scatter as they attempted to find cover. The recent shootings have already left a “number” of jihadis dead, according to Al Sumaria News. Despite the sniper’s efforts, sources said ISIS fighters shot and killed the boy before he was able to escape. The gunman has been targeting extremists in Mosul for several days now as Iraqi-led coalition forces continue their battle to retake the jihadi stronghold. “The emergence of the ‘Sniper of Mosul,’ as the residents call him, increased the pace of the popular resistance against ISIS,” Al Sumaria News reported. “The presence of the sniper in four neighborhoods emphasizes that there are many snipers and not only one.” Some believe the “Sniper of Mosul” could be part of an elite, Special Forces team — though it is unclear whether they would be Iraqi or allied soldiers.