Shipping companies said several things had to be clarified, including the presence of mines, Iranian conditions, practical implementations.

Shipping companies have cautiously welcomed Iran’s announcement that the Strait of Hormuz is open but said they would require clarifications, including about the risk of mines, before vessels move through the entry point to the Gulf.

Iran’s Foreign Minister Abbas Araghchi said on Friday that the Strait of Hormuz was open to all commercial vessels during a 10-day Lebanon ceasefire accord, prompting a fall in oil and other commodity prices while stock markets rose.

All commercial ships, including United States vessels, can sail through the strait, although their plans need to be coordinated with Iran’s Islamic Revolutionary Guard Corps, a senior Iranian official told the Reuters news agency.

Transit would be restricted to lanes which Iran deemed safe, adding that military vessels were still prohibited, the official said.

“We are currently verifying the recent announcement related to the reopening of the Strait of Hormuz, in terms of its compliance with freedom of navigation for all merchant vessels and secure passage,” said Arsenio Dominguez, secretary-general of the United Nations shipping agency, the International Maritime Organization.

The Norwegian Shipowners’ Association said several things had to be clarified before any ships could transit the strait, including the presence of mines, Iranian conditions and practical implementation.

“If this represents a step towards an opening, it is a welcome development,” said Knut Arild Hareide, CEO of the association which represents 130 companies with some 1,500 vessels.

Shipping association BIMCO cautioned members on returning to the strait.

“The status of mine threats… is unclear and BIMCO believes shipping companies should consider avoiding the area,” said Jakob Larsen, BIMCO’s chief safety and security officer.

The threat posed by mines in parts of the strait is not fully understood, and avoidance of the area by ships should be considered, a US Navy advisory on Friday, seen by Reuters, also said.

German shipping group Hapag-Lloyd on Friday said it was working for its ships to sail through the strait “as soon as possible”, but added that several questions remained.

“Our crisis committee is in session and will try to resolve all open items with the relevant parties within the next 24-36 hours,” it added.

Its Danish peer Maersk said it was closely monitoring the security situation and would act based on its risk assessment.

France’s CMA CGM and Norwegian oil tanker group Frontline declined to comment.

A recent route imposed by Tehran through its territorial waters near Larak Island would present navigational challenges even if vessels were not required to pay a toll, and would raise questions regarding compliance and insurance, said Matt Wright, lead freight analyst at data intelligence firm Kpler.

US President Donald Trump on Friday said Iran had agreed to never close the strait again, and that it was removing sea mines from it.

One of the world’s most important maritime chokepoints, disruption in the strait has forced shipping companies to suspend sailings, reroute cargo and rely on costly workarounds to keep goods moving in and out of the Gulf.