The United States conducted an airstrike against Islamic State (ISIS) Monday near Baghdad, NBC News reported. A U.S. aircraft hit an ISIS fighting position near the capital, and another U.S. air attack occurred near Mount Sinjar in northwestern Iraq, Defense officials told NBC.

The U.S. military has been carrying out airstrikes against Islamic State since Aug. 8. Last week, President Obama announced that an expanded campaign would attempt to "degrade and ultimately destroy" ISIS. The intensified action follows the beheadings of two American journalists and a British aid by the terrorist group.

Prime Minister David Cameron said the militants were "monsters not Muslims" and vowed retaliation. President Barack Obama said he would stand with Britain in the fight against ISIS.

"We will work with the United Kingdom and a broad coalition of nations from the region and around the world to bring the perpetrators of this outrageous act to justice, and to degrade and destroy this threat to the people of our countries, the region and the world," Obama said.

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