Armed guards have been warned not to engage with Houthi forces seeking to seize ships off Yemen.
Maritime security company Africa Risk Compliance (ARC) said any attempt to defend vessels could have serious consequences.
ARC has designated the Red Sea and Bab el-Mandeb Strait as “high risk” for all vessels calling at ports in Yemen and Israel, or merely transiting the area.
The Israel-linked, Ray Car Carriers-owned, 5,100-ceu Galaxy Leader (built 2002) was seized by Houthi forces earlier in November and is being used as a bargaining chip to try to end the Israel-Hamas war.
The Yemeni rebel group had warned of its intention to take Israeli-affiliated vessels before the attack.
ARC said: “All vessels calling at ports in Yemen or transiting through the Red Sea are at risk of being targeted, as even remote links to the country [Israel] may be used to justify an attack.”
The company believes the Houthis’ stance against Israel and support for Hamas poses a risk of escalation to a wider conflict in the Middle East.
The Iran-backed militant group has already made several missile and drone attacks against Israel this month.
“As this threat pertains to a wider geopolitical conflict and not piracy, there is little that can be done in the event of an attack by Houthi forces even if a vessel has embarked armed guards,” ARC added.
The Galaxy Leader was seized by armed men who were landed on deck by a helicopter.
Previous vessel seizures by Iran in the Gulf of Oman have included helicopters and multiple naval vessels.
“It would be ill-advised for any embarked team to attempt to defend the vessel against such forces,” the company said, as any response might be met with overwhelming force from a helicopter or naval vessels, which would greatly endanger the safety of the crew.
And attempts to combat the boarding force might be seen as provocative and could result in “poorer treatment” of the armed guards and crew later.
On Friday, the Eastern Pacific Shipping-owned, 15,300-teu container ship CMA CGM Symi (built 2022) was hit by a suspected Iranian-made kamikaze drone in the Indian Ocean, according to the AP news agency, citing a US defence official.
The 20,000-dwt Zodiac Maritime-owned tanker Central Park (built 2015) was boarded in the Gulf of Aden by five men who later surrendered to the US Navy.
The US said they are Somali pirates, but security sources believe this was a state-sponsored attack.