A U.S. Navy ship fired warning shots at an Iranian Revolutionary Guard Corps boat Wednesday after the vessel refused to back away in response to flares. CNN reports:

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.

This is the second time this week that Iranian boats have approached a U.S. Navy vessel. On Tuesday, four Revolutionary Guard boats came within 300 yards of the USS Nitze, a guided-missile destroyer. From CNN:

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…

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.

Tuesday’s incident was captured on video:

All of this is reminiscent of the Russian jets flying over a U.S. Navy destroyer in the Baltic sea back in April. In both cases, there seems to be a willingness among America’s geopolitical foes to challenge the U.S.

In January Iran took 10 U.S. sailors captive. The sailors were forced to kneel with their hands on their heads and Iranian TV later broadcast images of them in confinement.

Here’s the report that aired on CNN: