An Iranian boat that pointed a machine gun at the crew of a US Coast Guard cutter took off after the Americans fired a warning shot in response, the Navy says. Military officials say the Monomoy, one of the Coast Guard vessels patrolling international waters in the Persian Gulf, dispatched an inflatable boat to investigate the Iranian-flagged dhow—a traditional sailing vessel used for fishing and trading—and fired in self-defense after the dhow's gunner charged and aimed his weapon, Stars and Stripes reports. The Navy says no Americans were injured in the incident and that it's not clear whether the dhow was hit by the shot, reports CNN. The Monomoy had a friendlier encounter with Iranians in the Gulf in 2012 when it rescued six fishermen. (More Iran stories.)