Conflict & Security
Hormuz oil slicks likely after US tanker strikes
Satellite images appear to show likely oil slicks near the Strait of Hormuz after US strikes on tankers suspected of links to Iran's Revolutionary Guard, according to experts who analysed the images.
Images from the European Copernicus programme taken on Wednesday and Thursday showed brownish or winding streaks on the water about 20 kilometres off the Iranian coast, east of the strait. The area is near coral reefs listed under the Ramsar Convention as wetlands of international importance.
Several researchers and experts told AFP the streaks were most likely oil slicks, but satellite images alone cannot determine with certainty whether hydrocarbons are present or identify their precise origin.
Vincent Kerbaol, head of satellite maritime surveillance operations at the French company CLS, said the images were “strong indications” of “pollution probably left by ships”. Leon Moreland, a researcher at the UK-based Conflict and Environment Observatory, said the images showed “highly likely oil slicks” based on their appearance and spread and the lack of evidence for phytoplankton or algal blooms. SkyTruth, a US non-profit that conducts environmental surveillance, reached the same conclusion.
Two of the detected tracks start exactly where the tankers Riesco and Kylo transmitted their last signals before being sunk on September 8 and 5 respectively. Moreland said that, based on location and timing, Riesco seemed a probable source.
The US military said it destroyed five tankers in the Gulf of Oman on Tuesday in response to ballistic missile attacks by Iran's Revolutionary Guards against a US warship. US Central Command said the crews were directed to abandon ship before the tankers were hit and rendered inoperable.
The 240-metre Riesco sank after catching fire, according to images published by the US military on X. The last available signal from the vessel on the MarineTraffic site was at 2200 GMT on Tuesday at one end of the slick closest to the coast.
Iran condemned the US attacks as a threat to regional security. The Revolutionary Guards later warned oil tankers in Kuwaiti and Bahraini ports that they would be targeted in response to the US strikes and told crews to leave their vessels.
The clashes are part of a six-month war in which Iran has maintained control of the Strait of Hormuz while Washington has imposed a counter-blockade of Iranian ports and sanctions linked to Tehran.
Update
Satellite images analysed on Thursday appear to show oil slicks near the Strait of Hormuz after US strikes on tankers suspected of links to Iran's Revolutionary Guard.
Several researchers and experts told AFP the streaks were most likely oil slicks.
Two detected tracks start where the tankers Riesco and Kylo transmitted their last signals before being sunk on September 8 and 5 respectively.
Experts said satellite images alone cannot determine the presence of hydrocarbons with certainty or their precise origin.
One expert said the slicks could evaporate in three to four days if they were volatile fuels rather than crude oil.
Source note: AFP news report published on 10 September 2026 at 18:25:17 UTC.
Update
Iran condemned the US attacks on tankers as a threat to regional security.
Source note: AFP news report published on 9 September 2026 at 11:03:40 UTC.
Update
CENTCOM said crews were directed to abandon the vessels before they were struck and rendered inoperable.
CENTCOM said the strikes followed two failed IRGC ballistic missile attacks on a US Navy warship over the previous two days.
CENTCOM said the warship evaded the attempted attacks and continued patrolling regional waters.
US Secretary of State Marco Rubio said Iran would lose tankers each time it tried to hit US naval ships.
Source note: AFP news report published on 8 September 2026 at 23:08:20 UTC.
Update
The warning is attributed specifically to Iran's Islamic Revolutionary Guard Corps in a statement posted by IRNA.
The IRGC warning covered tankers in Kuwaiti and Bahraini ports whether anchored or docked.
The statement was described as being issued early Wednesday.
Source note: AFP news report published on 8 September 2026 at 22:53:33 UTC.
Update
Iran said it would target tankers off Kuwait and Bahrain.
Iran urged tanker crews in those areas to flee.
Source note: AFP news report published on 8 September 2026 at 22:40:07 UTC.
Update
US authorities said five vessels had already been hit.
Rubio said on a visit to Colombia that the United States would continue targeting Iranian tankers and that more strikes could be seen the same day.
Source note: AFP news report published on 8 September 2026 at 22:38:33 UTC.
Update
Rubio said the United States will continue to hit Iranian tankers.
Source note: AFP news report published on 8 September 2026 at 22:25:49 UTC.
Update
US Central Command said US forces destroyed five Iranian oil carriers on Tuesday.
US Central Command said American forces directed crews to abandon ship before the vessels were struck and rendered inoperable.
US Central Command said the strikes were in response to Iran’s most recent failed attacks after Tehran launched ballistic missiles at an American warship twice in recent days.
Source note: AFP news report published on 8 September 2026 at 22:27:54 UTC.
Update
Iranian Armed Forces chief of staff Ali Abdollahi warned that Iran would target US bases in the region if Iranian oil tankers were attacked.
Abdollahi said, according to Iranian state TV, that the US military had given Iranian oil tankers an evacuation warning before a possible attack.
Source note: AFP news report published on 8 September 2026 at 18:57:49 UTC.
Update
Iranian security chief Mohsen Rezaei said Iran would establish a prohibited zone near the Strait of Hormuz in coming days.
Rezaei said the zone would start from the US Navy's blockade line, include areas of the Persian Gulf and put entering ships on Iran's sanctions list.
Source note: AFP news report published on 6 September 2026 at 20:04:36 UTC.
Update
US Energy Secretary Chris Wright told ABC's "This Week" that Iran was "doing everything they can to cling on to something".
Wright said Iran knew its nuclear programme, navy and air force were "coming to an end".
Source note: AFP news report published on 6 September 2026 at 16:02:54 UTC.
Update
CENTCOM named the three oil tankers it said US forces disabled or destroyed: M/T Downy, M/T Stark 1 and M/T Kylo.
CENTCOM gave locations for the tanker strikes off Kharg Island, near Jask and in the Gulf of Oman.
Iran's foreign ministry called the US attacks on its oil tankers illegal and aggressive.
Iranian state television correspondents reported that crews were transported ashore by lifeboats and that the Kharg Island attack caused no casualties.
US President Donald Trump called the war “small potatoes” for Washington on Friday.
US Vice President JD Vance said Washington would not reopen talks with Iran until Iran ends attacks on commercial shipping in the Strait of Hormuz.
Source note: AFP news report published on 6 September 2026 at 12:29:12 UTC.
Update
Iran's top negotiator Mohammad Bagher Ghalibaf threatened faster and more forceful responses to US attacks.
Ghalibaf said what he called the era of proportionate responses had ended.
Ghalibaf urged Iranian authorities to manage imports better against the US economic campaign.
Revolutionary Guards spokesman Hossein Mohebi said Tehran was seeking to inflict economic damage on the United States during the war.
Source note: AFP news report published on 6 September 2026 at 10:54:37 UTC.
Update
Iran's Revolutionary Guards described the target as an American military unmanned surface vessel, or remotely operated vessel.
The Guards said the vessel was trying to enter a protected area of the Strait of Hormuz.
Iranian state television IRIB carried the Guards' statement.
Source note: AFP news report published on 6 September 2026 at 03:16:42 UTC.
Update
Iran's Revolutionary Guards said they attacked a US naval drone, according to Iranian state media.
Source note: AFP news report published on 6 September 2026 at 03:07:41 UTC.
Update
There were no immediate UKMTO reports of civilian tankers being targeted in the Strait of Hormuz after the IRGC claims.
CENTCOM did not immediately respond to AFP questions about the IRGC claim that it targeted six vessels.
The item adds wider context on US sanctions and Trump administration comments about the six-month conflict.
Source note: AFP news report published on 6 September 2026 at 01:29:58 UTC.
Update
Iran's Revolutionary Guards said they targeted three oil tankers on an unauthorised route in the Strait of Hormuz.
The Guards said they also targeted three vessels they described as affiliated with the United States in other areas.
The Guards warned other ships not to try to transit by unapproved routes.
Source note: AFP news report published on 5 September 2026 at 19:52:55 UTC.
Update
Iran's Guards said they attacked US-linked vessels in retaliation for strikes.
Source note: AFP news report published on 5 September 2026 at 19:43:58 UTC.
Update
Iran's foreign ministry condemned the US strikes as illegal and aggressive actions against Iranian commercial vessels.
Iranian state TV correspondents said crews were transported to shore on lifeboats and that the Kharg Island attack caused no casualties.
Iran's Khatam-al Anbiya central military command warned retaliation could be more severe and expand if US attacks continued.
US President Donald Trump called the Iran war “small potatoes” for the United States, and Vice President JD Vance said he “wouldn't call it a war”.
The US Treasury announced sanctions on a Turkish bank over alleged ties to Iran's Revolutionary Guards, and Washington has taken a step targeting a major Egyptian bank's UAE operations.
Source note: AFP news report published on 5 September 2026 at 19:27:30 UTC.
Update
Iran's military vowed "more severe" reprisals if US attacks continue.
Source note: AFP news report published on 5 September 2026 at 18:38:24 UTC.
Update
Iranian media reported several explosions near Kharg Island earlier Saturday.
US Vice President JD Vance said Washington was investigating Iran's allegation of a US strike on a wedding but was sceptical of the reports.
US President Donald Trump called the Iran war “small potatoes” for the United States and said it was “not a big thing”.
Vance said Iran's control over the Strait of Hormuz was “effectively gone” and that oil flows were returning to pre-war levels.
The item says Washington is seeking to choke Iran's economy through sanctions on entities with financial links to Iran.
Source note: AFP news report published on 5 September 2026 at 14:56:15 UTC.
Update
CENTCOM said the strikes followed failed Iranian attacks on American warships.
CENTCOM said no US soldiers were hurt after a destroyer and aircraft carrier evaded multiple Iranian attacks.
CENTCOM said video showed fireballs and flames after projectiles hit the ships.
CENTCOM commander Admiral Brad Cooper said the strikes imposed an economic cost on the IRGC.
The item adds that Washington says it is trying to economically strangle Iran, including through a blockade of its ports, while Iran has blocked commercial traffic through the Strait of Hormuz by threatening unauthorised shipping.
Source note: AFP news report published on 5 September 2026 at 14:22:00 UTC.
Uncertainty notes
Satellite images alone cannot determine with certainty whether hydrocarbons are present or identify their precise origin.
The precise source of the apparent slicks has not been confirmed.
If the slicks are volatile fuels, one expert said they could evaporate in three to four days, unlike crude oil.
Source
AFP news report published on .