ISIS militants attacked the outskirts of Iraq's northern oil refinery town of Beiji overnight with car bombs and clashed with the army and Shiite militias in the town's western districts, the local mayor and security sources said Friday. The town of Beiji and its refinery – Iraq's largest – have been a battlefront for over a year. The hard-line Islamists seized the town in June 2014 as they swept through much of northern Iraq toward Baghdad. Control of Beiji neighborhoods has changed hands many times during the conflict. Authorities said last month they had recaptured most of the town, but the radical militant group attacked central neighborhoods days later, forcing pro-government forces to pull back. At least three militia fighters were killed on Friday when ISIS launched car bomb attacks against a makeshift headquarters in al-Rayash, about 18 km south of Beiji, a militia leader and a source in the Salahuddin Operations Command said. Mortars in an adjacent area killed two civilians, according to the source in the operations command, the Iraqi military's command center for the province of Salahuddin, where Beiji is situated. Beiji Mayor Mahmoud al-Jabouri said ISIS used 12 car bombs and more than 200 fighters in the offensive. "The attack started at 2 a.m. (2300 GMT)," he said. "They came from the direction of Camp Speicher," a former U.S. base outside the city of Tikrit. Jabouri said "tens" of security forces and militia fighters were killed or wounded in the violence, which also saw ongoing clashes in Beiji's western districts of Sikak and Tamim. Also Friday, local authorities in Iraq's western Anbar province said government airstrikes destroyed a women and children's hospital in ISIS-held territory near the city of Fallujah. At least 22 women and children were killed, a local hospital official said. The Anbar provincial council said Iraqi warplanes were targeting ISIS militants in the village of Nassaf, 2 kilometers south of Fallujah, when the hospital there was hit Thursday. In a statement sent to journalists, the council added that at least 53 women and children were killed and wounded in the attack, without providing a breakdown of the alleged casualties. It called on the Iraqi defense ministry to accept responsibility for the attack and to exert caution when targeting civilian areas. A senior official overseeing operations at several Fallujah-area hospitals said at least 22 women and children were killed in the airstrike. He spoke on condition of anonymity because he's not authorized to talk to reporters. Falah al-Assawi, a member of the Anbar provincial council, confirmed the attack, also blaming government warplanes. In July 2014, Human Rights Watch said Iraq's security forces killed at least 75 civilians and wounded hundreds of others in indiscriminate airstrikes on five cities – among them, Fallujah. Among the first orders given by Prime Minister Haider al-Abadi after he was named Iraqi premier in September was for Iraqi security forces to stop shelling areas populated by civilians. A spokesman for the Iraqi defense ministry, Yahya Rasool, Friday rejected claims of the airstrike. He said Iraqi troops do not target hospitals, schools or other civilian facilities, even if they are occupied by militants. "Airstrikes by Iraqi forces are conducted on targets linked to the [ISIS] terrorist organization," he said. "We carry out airstrikes based on information that we receive from intelligence forces ... We have specific instructions to avoid hitting any targets that provide services to the civilians." Aamaq, an ISIS-affiliated news agency, posted an online video late Thursday purportedly showing the aftermath of the attack with men, women and children covered in blood, bandages and scars. The Associated Press could not independently verify the video.