Iran believed to be responsible for last week's attack on U.S. military base in Syria

Iran is believed by the U.S. to be responsible for last week's attack on al-Tanf, a base in southern Syria where U.S. troops are located, according to a U.S. official.

U.S. officials confirm that five drones were launched from within Syria in the attack on al-Tanf.

Last week, U.S. Central Command called the attack  "deliberate and coordinated," but no injuries were reported among U.S. troops, U.S. Central Command spokesman Navy Captain Bill Urban said in a statement on the day of the attack.