A AV-8B Harrier II from the 13th Marine Expeditionary Unit launches from the USS Boxer (LHD 4) during its first day of striking ISIS held positions in Iraq from the Arabia Gulf, June 16, 2016. Reuters

The U.S. military denied reports Monday that Islamic State militants had downed a warplane in Iraq's Anbar province. The terrorist group also known as ISIS claimed it killed all U.S. crewmembers abroad the plane.

The plane was allegedly operating near the Ain Al-Asad air base, which is run jointly by Iraq and the Pentagon, according to Sputnik News, a Russian state site. The Defense Department called the claims baseless and said there was no evidence of a missing warplane. The U.S. military carried out 73 airstrikes in Iraq last week under Operation Inherent Resolve.

ISIS has brought down planes in the past. Last week, Amaq, an agency linked to the radical militant group, released video footage that showed plane wreckage and parts of a corpse in a military uniform and a white helmet in Syria. The Syrian Observatory for Human Rights, a British-based organization that monitors the Syria civil war, said the plane came down near the eastern city of Deir al-Zor.

Defense Secretary Ashton B. Carter announced earlier this month that the Pentagon would send an additional 560 U.S. troops to Iraq to help take back the city of Mosul, the de facto capital of the Islamic State in Iraq. There are roughly 4,600 U.S. troops in Iraq, according to the Washington Post.

"We’re going to need airfield operations, and if you want to go in concentric circles around that we’re going to also have a logistics footprint there to facilitate the flow of goods and supplies and personnel through that airfield," Army Lt. Gen. Sean MacFarland, the top U.S. commander in Iraq, said at the time. "We’ll have a security envelope around that. We’ll have a communications capability there and a command-and-control or headquarters unit there, as well. There’s nothing really very sexy in any of that, but it’s all very necessary to keep the campaign moving forward."