Iran shot down a United States military drone on Thursday. The incident comes as tensions between the two countries have increased following American withdrawal from Iran’s nuclear deal with world powers. Iran’s Revolutionary Guard said it shot down the drone over Iranian airspace. But a U.S. official said the unmanned aircraft was brought down in international airspace over the Strait of Hormuz. Brigadier General Hossein Salami is head of the Revolutionary Guards. He called the downing of the drone a “clear message” to Iran’s enemy. He said, “Our air space is our red line and Iran has always responded and will continue to respond strongly to any country that violates our air space.” Captain Bill Urban, a spokesman for the U.S. Central Command, called the incident an “unprovoked attack.” In a statement, he said, “Iranian reports that the aircraft was over Iran are false.” Instead, Urban said, the drone was in international airspace.