The U.S. Department of Transportation's Maritime Administration issued a warning regarding threats to commercial ships in the Persian Gulf. Iran is using GPS jammers and has placed such systems on Abu Musa Island near the Strait of Hormuz, according to a U.S. official. The jammers reportedly do not affect U.S. military ships and aircraft. Iran is also “spoofing” the automatic identification system on its military vessels to disguise them as commercial ships, and there have been reports of "unknown entities falsely claiming to be US or coalition warships."