Iran threatened to shoot down two U.S. Navy surveillance aircraft flying a routine mission in international airspace Saturday over the Persian Gulf.

“It’s one thing to tell someone to get off your lawn, but we weren’t on their lawn,” one senior defense official told Fox News. “Anytime you threaten to shoot someone down, it’s not considered professional.”

The two surveillance aircraft collectively carried a crew of 33. The official elaborated that the crew’s mission was to “test the Iranian reaction” to U.S. surveillance near its airspace. Iran’s threat is the latest in a series of close call interactions between the U.S. military and Iran.

Seven Iranian attack boats swarmed a U.S. patrol boat in the Persian gulf Sept. 6. The patrol boat was forced to change its course after the attack boats aggressively sped towards it, risking a collision or a shooting incident. The patrol boat was in international waters at the time. The U.S. Navy called the incident “unsafe and unprofessional.”

Four Iranian attack boats also threatened a U.S. Destroyer in international waters on August 25. The four boats raced towards the destroyer without responding to radio calls, the ship’s whistle, or warning flares launched from the destroyer. A video of the incident shows Iranian boats evading U.S. flares and coming within a dangerously close distance of the Nitze.

The U.S. Navy report from 2015 noted that 10 percent of all interactions between the U.S. and Iran on international waters were deemed unprofessional and unsafe. Iran reportedly approached two U.S. Navy ships two months ago in the Persian Gulf, one of which was carrying U.S. Central Command Chief Army Gen. Joseph Votel.

The Iranian Navy was also responsible for the detention of 10 U.S. sailors in January, 2016. The sailors drifted into Iranian waters after a mechanical failure and sparked an international incident. Iran broadcast the sailor’s detentions on television, including video of a Navy Lieutenant apologizing on camera, in violation of U.S. military regulations.

Follow Saagar Enjeti on Twitter

Send tips to [email protected]

Copyright 2016 Daily Caller News Foundation