The Arleigh Burke-class guided-missile destroyer USS Mahan (DDG 72) had what one report described as a "close encounter" with an Iranian vessel on April 24.
According to a report by Fox News, the Iranian vessel was a "fast attack craft" used by the Iranian Revolutionary Guard Corps Navy. USS Mahan was forced to change course, the crew manned weapons, fired flares, and sounded a danger signal. The Iranian vessel stayed over 1,000 yards from the Mahan, but its weapons were manned.
According to the 16th Edition of Combat Fleets of the World, Iran has over 100 "fast attack craft" of varying types. The most notorious of these are roughly 30 Boghammers, which can reach speeds of up to 45 knots, and are armed with .50-caliber machine guns or twin 23mm anti-aircraft guns and either a 12-round 107mm rocket launcher, a 106mm recoilless rifle, or a RPG-7. American forces destroyed at least five of these vessels during naval clashes with Iran in 1987 and 1988.
This is not the first time USS Mahan has had a close call with Iranian vessels. In January, 2017, the Mahan had to fire warning shots at similar craft that came within 900 yards. The Iranian vessels backed off.
In March, 2017, the missile-range instrumentation vessel USNS Invincible (T AGM 24) was harassed by Iranian forces twice. In one incident, an Iranian frigate came within 150 yards of the Military Sealift Command vessel. The second incident saw IRGC speedboats approach within 600 yards of the Invincible.
That same month, the commander of United States Central Command, Army Gen. James Votel told the Senate Armed Services Committee that Iran was the primary concern in the region.
"We are also dealing with a range of malign activities perpetrated by Iran and its proxies operating in the region," said Votel, citing Iran's support for terrorist groups like Hezbollah and Bashir Assad's regime in Syria. "It is my view that Iran poses the greatest long-term threat to stability for this part of the world."