Dozens of commercial ships have dropped anchor at a distance outside Iran's port limits in recent days, according to data and shipping sources, as tensions with the United States grow.
Such movements were precautionary given the tensions amid ongoing protests in Iran, the shipping sources said. Port limits are significant because they run a higher risk of collateral damage in the event of air strikes on nearby infrastructure.
The US is withdrawing some personnel from bases in the Middle East, a US official said on Wednesday. This followed a senior Iranian official saying Tehran had warned its neighbours that it would hit American bases if Washington strikes Iran.
The country relies on seaborne trade for imports using dry bulkers, general cargo and container ships as well as oil tankers for oil exports.
The number of tankers moving into Iran's exclusive economic zone (EEZ) jumped from one vessel to 36 tankers between January 6 and January 12. This is based on analysis by maritime intelligence solutions provider Pole Star Global.
The EEZ is a stretch of water along its Gulf and Caspian coasts that extends up to 24 miles (39 kilometres) and beyond local territorial limits of 12 nautical miles (22 kilometres). At least 25 bulk carriers were stationary in Iran's EEZ off the major port of Bandar Imam Khomeini.
This was shown by data from ship tracking and maritime analytics provider MarineTraffic. A further 25 ships including container and cargo vessels had dropped anchor further south off the port of Bandar Abbas, MarineTraffic data showed.
Israel launched air strikes in June 2025 on targets in Bandar Abbas. This is where at least 70 people were killed in unexplained blasts in April and authorities did not rule out sabotage.
As Iran's leadership tries to put down the worst unrest the Islamic Republic has faced, Tehran is seeking to deter US President Donald Trump's repeated threats to intervene. These threats were made on behalf of anti-government protesters.
The level of interference with GNSS navigation systems, which included GPS, had increased to "substantial" in the Gulf and Strait of Hormuz area over the past week. This was reported by the US Navy's Combined Maritime Force in a note on Monday.
"This is highly likely due to force protection measures being taken in relation to the ongoing political tensions in the region. Vessels transiting this area could be impacted," the note said.
(Reporting by Jonathan Saul; Editing by Alexander Smith)
