The International Maritime Organisation (IMO) on Monday, 5 May urged vessels operating near the Strait of Hormuz to exercise "maximum caution", following reports of a US transit facilitation operation aimed at guiding stranded ships through one of the world's most critical maritime chokepoints. The warning comes as tensions in the area escalate sharply, with an explosion and fire reported aboard a South Korean-operated vessel anchored in the strait.

IMO Issues Formal Caution

In a written response to Xinhua news agency, an IMO spokesperson stated: "We are aware of the reports but do not have further details. We continue to urge ships to practice maximum caution in the area." The organisation did not elaborate on the specific risks, but the statement underscores the gravity of the situation in a waterway through which an estimated 20% of the world's oil supply passes.

US Transit Operation and Iranian Warning

US President Donald Trump announced on Sunday that the United States would launch a transit facilitation operation beginning Monday to "guide" stranded ships through the Strait of Hormuz. The UK Maritime Trade Operations (UKMTO) subsequently confirmed that the US had established an enhanced security area south of the Traffic Separation Scheme within the strait to support vessel transits.

However, the UKMTO cautioned that the maritime security threat level in the area remains "critical" due to ongoing regional military activity. In a direct counter-move, the Iranian military command warned on Monday that any foreign armed forces — particularly those of the United States — would face attack if they attempted to approach or enter the strait. The warning signals a significant escalation in an already volatile corridor.

Explosion and Fire Aboard HMM Vessel

Compounding the crisis, an explosion followed by a fire broke out aboard a Panama-flagged vessel operated by HMM Company Limited, a major South Korean shipping firm, at approximately 8:40 p.m. on Monday. The ship was anchored in waters near the United Arab Emirates (UAE) within the strait at the time of the incident, according to the South Korean Foreign Ministry as quoted by Yonhap news agency.

The vessel had 24 crew members on board — six South Korean nationals and 18 foreign nationals. Authorities confirmed that no casualties have been reported so far. South Korean Foreign Ministry officials said they are working to verify whether an external attack caused the explosion. The cause of the blast and the extent of the damage remain under investigation.

Why the Strait of Hormuz Matters

The Strait of Hormuz, located between Iran and the Arabian Peninsula, is the world's most strategically significant maritime chokepoint. Any sustained disruption to navigation there carries severe consequences for global energy markets and supply chains. This is not the first time the strait has been the site of vessel incidents amid US-Iran tensions — a pattern that has repeated itself since at least 2019, when a series of tanker attacks drew international condemnation.

With the US now operating in the area and Iran issuing direct military threats, the situation is being closely monitored by shipping companies, insurers, and governments worldwide. The coming days will be critical in determining whether the US transit operation stabilises vessel movement or further inflames tensions.