U.S. fighter planes pounded targets in northern Iraq as a joint military operation kicked off to retake the country's largest dam from ISIS militants, officials said. U.S. military officials said FA-18 fighter bombers and armed drones conducted nine airstrikes against armored personnel carriers and military vehicles, and offered air cover to Iraqi and Kurdish forces fighting to regain control of the Mosul Dam.

ISIS fighters seized the dam on the Tigris River on Aug. 7 as part of an offensive that has seen large swaths of Iraq fall to the Sunni militants. Sources told NBC News the decision to try retaking the dam came after intelligence showed ISIS militants were not yet at a point where they could blow up the installation. The Mosul Dam is critical to Iraqi's entire infrastructure, so much so President Obama flagged its control as a key concern a week ago as he took off for vacation in Martha's Vineyard.

U.S. Central Command said destroyed or damaged a total of 14 vehicles, including armored personnel carriers, Humvees and armed vehicles, and all aircraft returned safely.

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- Jim Miklaszewski and Courtney Kube