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 US 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 Wednesday, after a senior Iranian official said 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), a stretch of water along its Gulf and Caspian coasts that extends up to 24 miles and beyond local territorial limits of 12 nautical miles, jumped from 1 vessel to 36 tankers between January 6 and January 12, analysis by maritime intelligence solutions provider Pole Star Global shows.
At least 25 bulk carriers were stationary in Iran's EEZ off the major port of Bandar Imam Khomeini, data from ship tracking and maritime analytics provider MarineTraffic showed.
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, 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 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, the US Navy's Combined Maritime Force said 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.
Atleast 3,428 killed 'in crackdown on protesters'
Iranian security forces have killed at least 3,428 protesters in a crackdown on demonstrations, the Norway-based Iran Human Rights (IHR) NGO said Wednesday, adding that more than 10,000 people had also been arrested, AFP reported from Paris.
IHR said the jump in its verified toll was due to new information it received from within the Iranian health and education ministries, with at least 3,379 of the killings coming during the height of the protest movement from January 8 to 12.
The group's director Mahmood Amiry-Moghaddam condemned the "mass killing of protesters on the streets in recent days", while IHR warned that even the new figure represented an "absolute minimum" for the actual toll.
