The self-proclaimed Islamic State in Iraq and Sham (ISIS) militants have captured 170 youths from two villages located in the Iraqi city of Kirkuk on Saturday, according to a security source.The youths are from the al-Jubur tribe and were taken to a prison in Hawija district located 55 km from the city of Kirkuk.They also executed 15 Iraqi civilians on Friday in Fallujah in the western province of Anbar, security sources said."ISIS militants executed 15 civilians by shooting, in public," a security source who preferred not to divulge his name told Anadolu Agency on Saturday.The execution took place in public, in Fallujah's al-Karma district, after a militant from the group made a statement claiming that the 15 people had cooperated with Iraqi security forces and had revealed information about ISIS's whereabouts.ISIS had captured 50 people from the al-Jubur tribe last month but had released them after two days of interrogation, security sources said.Meanwhile, the Iraqi security forces backed by tribal fighters managed to repel an ISIS attack on Saturday, in the city of Ramadi, the capital of Anbar province, police said."Iraqi forces managed to kill 10 ISIS militants and destroyed a vehicle. A policeman was injured in the clashes, which lasted for five hours," Anbar province's police chief Kazim Mohamed al-Fahdawi, said.The number of deaths could not be independently verified.A security vacuum has gripped Iraq since June 2014, when ISIS stormed the northern province of Mosul and declared what it called a caliphate in Iraq and Syria.