Islamic State militants have shot down an Iraqi military helicopter with a rocket launcher in northern Iraq. An Iraqi Defense Ministry official said Friday the Mi-35 helicopter was brought down between the towns of Beiji and al-Senniyah, according to the Associated Press. Beiji is located 130 miles north Baghdad and is home to Iraq's biggest oil refinery.

If confirmed, the incident would be the first air attack by the Islamic State group, raising questions about the future of a U.S.-led airstrike campaign in Syria and Iraq aimed at wiping out the militants also known as ISIS. Recent reports indicate that ISIS hasn't been deterred by the airstrikes and instead has continued its months-long campaign to take Baghdad. Last month, ISIS overran an Iraqi military base and executed 300 soldiers and launched 14 mortar rounds during a foiled attempt to break into the Adala Prison in northern Baghdad. 

The Islamic State carried out 641 operations in Baghdad in 2013, up from 371 operations in 2012, including car bombs, armed assaults and assassinations, according to the nonprofit Institute for the Study of War in Washington, D.C. ISIS gained international prominence in June when it seized northern cities such as Tikrit, Saddam Hussein's hometown, and Mosul, Iraq's second largest city, and began holding mass executions of Iraqi soldiers.