(CNN) A US Navy patrol craft fired three warning shots at an Iranian Revolutionary Guard Corps boat Wednesday after US officials said it had harassed that patrol craft, CNN has learned.

Another US patrol craft and a Kuwaiti Navy ship were also harassed in the incident, which took place in the northern end of the Persian Gulf.

At one point, the Iranian boat came within 200 yards of one of the US Navy boats. When it failed to leave the area after the Navy had fired flares and had a radio conversation with the Iranian crew, the US officials said, the USS Squall fired three warning shots. Following standard maritime procedures, the Navy fired the three shots into the water to ensure the Iranians understood they needed to leave the immediate area.

State Department spokeswoman Elizabeth Trudeau said incidents like this one "unnecessarily escalate tensions," adding that the US doesn't know Iran's intentions.

In an encounter Tuesday, a US Navy official told CNN four Iranian Revolutionary Guard Corps vessels conducted a "high-speed intercept" of the USS Nitze in waters near the Strait of Hormuz Tuesday, deeming the incident "unsafe and unprofessional."

The official said two of the vessels slowed and turned away only after coming within 300 yards of the US guided-missile destroyer as it transited international waters near the Strait of Hormuz, and only after the destroyer had sent multiple visual and audio warnings.

The incidents are only the latest in a series of all-too-close encounters with Iran in the region since December. These brushes have included Iranian rocket launches, drones flying over US vessels and the capture of US sailors in January. They come against the backdrop of renewed US diplomatic contacts with Iran, which has triggered a political backlash among Iranian hardliners, including the powerful IRGC.

In the wake of Tuesday's incident, the Nitze and US Naval Forces Central Command have determined that the Iranian vessels were violating international law and maritime standards, acting dangerously and unprofessionally.

JUST WATCHED Iran video appears to show U.S. sailor in tears Replay More Videos ... MUST WATCH Iran video appears to show U.S. sailor in tears 02:23

The Iranian vessels moved at high speed toward the Nitze, which was operating in accordance with international law in international waters and ignored maritime "rules of the road" as set out in the 1972 Convention on the International Regulations for Preventing Collisions at Sea. According to the Navy official, the IRGC vessels ignored multiple warnings, creating a dangerous, harassing environment that could have pushed the Nitze to take defensive measures, escalating the situation.

The US Naval Forces Central Command is responsible for approximately 2.5 million square miles of area that stretches from the Arabian Gulf to the Red Sea, Gulf of Oman, parts of the Indian Ocean and 20 countries.

Tuesday's encounter took place as the Nitze and the guided-missile destroyer USS Mason were conducting what the official said was a routine transit near the internationally recognized strait. The official spoke to CNN anonymously to discuss military matters.

The four IRGC vessels approached at high speed. After identifying them, the Nitze tried 12 times to make contact by radio without receiving a response, according to the Navy official. As two of the Iranian vessels continued to barrel toward the Nitze at high speed, the destroyer used an internationally recognized maritime danger signal three times.

Photos: US aircraft carriers Photos: US aircraft carriers Sailors spell out #USA with the American flag on the flight deck of the Nimitz-class aircraft carrier USS Theodore Roosevelt in the Persian Gulf in late June 2015. When the Roosevelt leaves the Gulf sometime in October, the U.S. Navy will be without a carrier in the important region for two months. Hide Caption 1 of 31 Photos: US aircraft carriers A MV-22B Osprey, from Marine Operational Test and Evaluation Squadron 1, lifts off from the flight deck of the aircraft carrier USS Carl Vinson (CVN 70) on June 12, 2016. Click through the gallery to see other US aircraft carriers. Hide Caption 2 of 31 Photos: US aircraft carriers Tug boats maneuver the aircraft carrier Pre-Commissioning Unit Gerald R. Ford (CVN 78) into the James River during the ship's turn ship evolution on June 11, 2016. This is a major milestone that brings the country's newest aircraft carrier another step closer to delivery and commissioning later this year. Hide Caption 3 of 31 Photos: US aircraft carriers The Nimitz-class aircraft carrier USS Ronald Reagan (CVN 76) arrives at the U.S. Navy base in Yokosuka, a suburb of Tokyo, Japan, on October 1, 2015. The Reagan is the fifth U.S. carrier forward deployed to Japan following USS George Washington (CVN 73), USS Kitty Hawk (CV 63), USS Independence (CV 62) and USS Midway (CV 41), according to the Navy. Hide Caption 4 of 31 Photos: US aircraft carriers The aircraft carrier USS Dwight D. Eisenhower (CVN 69) (Ike) transits through the Strait of Gibraltar into the Mediterranean Sea on June 13, 2016. Ike, the flagship of the Eisenhower Carrier Strike Group, is conducting naval operations in the U.S. 6th Fleet area of operations. It could be used to support operations against ISIS in the Mideast. Hide Caption 5 of 31 Photos: US aircraft carriers A rainbow forms over the bow of the Nimitz-class aircraft carrier USS John C. Stennis as the ship steams in the Pacific Ocean on February 3, 2015. Hide Caption 6 of 31 Photos: US aircraft carriers U.S. aircraft carrier classes – U.S. Secretary of Defense Ash Carter (left) and Philippine Secretary of National Defense Voltaire Gazmin shake hands on a Marine Corps V-22 Osprey as they depart the the aircraft carrier USS John C. Stennis (CVN 74) after touring the aircraft carrier as it sailed in the South China Sea on April 15, 2016. Hide Caption 7 of 31 Photos: US aircraft carriers A photo illustration of the U.S. Navy's Gerald R. Ford-class aircraft carrier USS John F. Kennedy (CVN-79). The ship's keel laying ceremony was celebrated Saturday, August 22, 2015, in Newport News, Virginia. The ship is expected to replace the USS Nimitz (CVN-68), scheduled for inactivation in 2025, in the Navy fleet. The newest Kennedy will be the second carrier of that name. The first John F. Kennedy (CVA-67) was the last conventionally powered carrier. It was decommissioned in 2007. Hide Caption 8 of 31 Photos: US aircraft carriers The aircraft carrier USS Harry S. Truman (CVN 75) passes under the Friendship Bridge while transiting the Suez Canal on Dec. 14, 2015. The ship is conducting operations in the Persian Gulf, where Iran claims to have taken footage of the carrier using a drone. Click through the gallery for more images of U.S. Navy aircraft carriers. Hide Caption 9 of 31 Photos: US aircraft carriers Aviation Structural Mechanic Airman V. Sek, assigned to the "Jolly Rogers" of Strike Fighter Squadron (VFA) 103, applies a Christmas decal to an F/A-18F Super Hornet in the hangar bay of the Nimitz-class aircraft carrier USS Harry S. Truman in December 2015. Hide Caption 10 of 31 Photos: US aircraft carriers The Nimitz-class aircraft carrier USS George Washington (CVN 73) is seen from inside its sister ship, the USS Ronald Reagan (CVN 76), on August 7 off the coast of California as the two ships prepare for a "hull swap." Over 10 days in San Diego, much of the crew of each ship will transfer to the other. When completed, the Reagan will head to forward deployment in Japan, where the Washington had been. The Washington will head to Newport News, Virginia, for an overhaul. Hide Caption 11 of 31 Photos: US aircraft carriers Three Nimitz-class aircraft carriers USS Carl Vinson (CVN 70), top, USS Ronald Reagan (CVN 76), center, and USS John C. Stennis (CVN 74) are pierside at Naval Air Station North Island near San Diego on June 12, 2015. The Vinson has just recently returned from a 10-month deployment. The Reagan is preparing for a move to Japan later this year and the Stennis was making a port call after steaming from its homeport of Bremerton, Washington. Hide Caption 12 of 31 Photos: US aircraft carriers Sailors test the countermeasure washdown system on the flight deck of the Nimitz-class aircraft carrier USS Dwight D. Eisenhower (CVN 69) during sea trials prior to returning to its homeport at Naval Station Norfolk in late August 2015. Hide Caption 13 of 31 Photos: US aircraft carriers The aircraft carrier USS Theodore Roosevelt departs Naval Station Norfolk, Virginia, on Wednesday, March 11, for a scheduled deployment. The Nimitz-class carrier's departure was delayed for two days after marine growth clogged sea water intakes. Divers went into the 36-degree water to clean out the intakes and allow the ship to get under way. The cold water created a fog that made it seem the ship was in a cloud. Hide Caption 14 of 31 Photos: US aircraft carriers The USS Abraham Lincoln, a Nimitz-class aircraft carrier, is seen near the coast of Indonesia in 2005. The carrier recently received a new anchor from the decommissioned USS Enterprise. Hide Caption 15 of 31 Photos: US aircraft carriers Lightning strikes over the flight deck of the USS John C. Stennis, another Nimitz-class aircraft carrier, as the ship moves through the Persian Gulf in 2007. All of the Navy's 10 active aircraft carriers are from the Nimitz class, which started in 1975 with the commission of the USS Nimitz. Hide Caption 16 of 31 Photos: US aircraft carriers The USS Ranger (CV-61) arrives at Pearl Harbor, Hawaii, in 1993. The Forrestal-class carrier, which featured in the movie "Top Gun," is to be scrapped this year. Hide Caption 17 of 31 Photos: US aircraft carriers In this photo released by the U.S. Navy, a tugboat works alongside the decommissioned aircraft carrier USS Saratoga on Thursday, August 21, in Newport, Rhode Island. The Navy has paid a Texas recycling company a penny to dispose of the Saratoga, part of the Forrestal-class of "supercarrier" vessels built for the Atomic Age. The carrier was decommissioned 20 years ago. Hide Caption 18 of 31 Photos: US aircraft carriers Aircrew members are lifted from the flight deck of the USS John F. Kennedy during an exercise in 2002. The ship, which was decommissioned in 2007, was the only member of its class. Hide Caption 19 of 31 Photos: US aircraft carriers An F/A-18 Hornet launches from the USS Enterprise in 2007. The Enterprise, the world's first nuclear-powered aircraft carrier, was decommissioned in 2012. Like the John F. Kennedy, it was the only ship built in its class. Hide Caption 20 of 31 Photos: US aircraft carriers The Kitty Hawk class was named for the USS Kitty Hawk, seen here departing Yokosuka, Japan, in 2008. At that time, the Kitty Hawk was the oldest carrier in the U.S. Navy and the only conventional-power aircraft carrier still in commission. It was decommissioned in 2009. Hide Caption 21 of 31 Photos: US aircraft carriers The USS Independence, a member of the Forrestal class that preceded the Kitty Hawk class, heads up the East River in New York in 1959. Hide Caption 22 of 31 Photos: US aircraft carriers Helicopters sit on the flight deck of the USS Saipan during the mid-1950s. The ship was one of two members of the Saipan class. Hide Caption 23 of 31 Photos: US aircraft carriers The USS Midway, namesake of the Midway class of aircraft carriers, floats off the coast of North Vietnam in 1972. It was named after the Battle of Midway, when U.S. forces held back a Japanese attempt to take the Pacific atoll in 1942. Hide Caption 24 of 31 Photos: US aircraft carriers The USS Princeton, part of the Independence class, moves off the coast of Seattle in 1944. Hide Caption 25 of 31 Photos: US aircraft carriers The Essex-class USS Franklin burns after being hit by a Japanese dive bomber in 1945. The ship was named after Benjamin Franklin and nicknamed "Big Ben." Hide Caption 26 of 31 Photos: US aircraft carriers The USS Wasp burns in the Coral Sea after being struck by three torpedoes from a Japanese submarine in 1942. The ship, the only one of its class, would ultimately sink because of the damage. Hide Caption 27 of 31 Photos: US aircraft carriers B-25 bombers sit on the deck of the USS Hornet in the Pacific Ocean in 1942. The Hornet, one of three carriers in the Yorktown class, was the ship that launched the bombers flown by Air Force Lt. Col. James Doolittle and his pilots during an air raid in Tokyo four months after the attack on Pearl Harbor. It also was involved in the Battle of Midway. Hide Caption 28 of 31 Photos: US aircraft carriers Navy personnel work on board the USS Ranger circa 1942. The Ranger was the first ship to be designed and built specifically as an aircraft carrier. It was the only ship in its class. Hide Caption 29 of 31 Photos: US aircraft carriers There have actually been two aircraft carriers named after the Revolutionary War's Battle of Saratoga. The first USS Saratoga, seen here moving toward San Francisco's Golden Gate Bridge in 1945, was one of two members of the Lexington class of aircraft carriers. Hide Caption 30 of 31 Photos: US aircraft carriers The USS Langley, the Navy's first aircraft carrier and sole member of its class, steams off the coast of Baltimore in 1924. Hide Caption 31 of 31

That signal -- five short blasts of the ship's whistle -- is used when another vessel's intentions are not understood or its indicated course is dangerous. At the same time, the Nitze also used visual warnings, firing 10 flares in the direction of the approaching vessels. Again, the destroyer got no response, the official said.

Despite the Nitze's close proximity to off-shore oil rigs, the ship altered course to move away from the approaching Iranian vessels and avoid a potential collision. Only after the two Iranian vessels had closed to within 300 yards of Nitze did they slow their speed before ultimately moving away.

The intercept was another tense incident between the longtime foes over the past year.

In December, as part of a life-fire exercise, Iran's military fired a rocket near the American aircraft carrier, the USS Harry Truman

And in January, the IRGC captured 10 American sailors when their two Riverine Command Boats accidentally strayed into waters near Iran-controlled Farsi Island, in the Persian Gulf. The sailors were released soon after.

Later that month, Iran reportedly flew an unarmed drone over a US warship, a move that a US navy official called "abnormal and unprofessional."