and Ar-Rutbah in offensive operations in 2016 and then Fallujah as well in the Third Battle of Fallujah ending in June 2016. On 16 October 2016, the Battle of Mosul began. 2017 The 2017 Mosul massacre was the largest single death toll inflicted by a coalition air strike since the 2003 invasion of Iraq by U.S. forces. In April, the Iraqi Army, with the help of the Popular Mobilization Forces, launched the Western Nineveh offensive to capture territory west of Mosul. The PMU were able to reach the Iraq–Syria border, meeting up with territory controlled by the Syrian Democratic Forces. In May, a member from the Canadian Special Forces Joint Task Force 2 disrupted a Daesh attack on Iraqi security forces. The target was successfully hit at 3,540 metres from a high-rise, setting the world's longest recorded sniper kill. On 10 July, Iraqi Army forces captured Mosul. Following the victory in Mosul, the Iraqi Army launched operations to sweep what remained of ISIL-controlled territory in the country. The Tal Afar offensive was launched on 20 August and completed by 31 August with a major Iraqi Army victory. The Hawija offensive started in late September and was complete by 5 October. In September 2017, a United Nations Security Council Resolution was adopted to "Reaffirm its respect for the sovereignty, territorial integrity, independence and unity of Iraq". Following the adoption of the resolution, a UN investigative team was established to document human rights violations and serious crimes committed by ISIS in Iraq. However, by the end of 2018, the team had not yet launched its investigation. On 25 September, Iraqi Kurdistan held an unofficial independence referendum. Turnout was reported to be 72.83% with 92.73% voting in favor of independence from Iraq. In response to the referendum, the Iraqi Army launched a short offensive on 15 October against Iraqi Kurdistan to recapture the disputed city of Kirkuk with the help of the Talabani family and some PUK members. Following the capture of Kirkuk and Sinjar, Masoud Barzani announced his intentions to step down as President of Iraqi Kurdistan, effective 1 November, after being in power for 12 years. His gamble of pushing through with the unofficial referendum ended with the disputed territories being recaptured by Iraq and with the Kurdish statebuilding project being left abandoned. Iraq captured ISIL's last two strongholds of Al-Qa'im and Rawah on 17 November. After the Iraqi army had