Maritime security and industry groups raised the risk level for ships calling at Israeli ports on Friday, with terminals facing possible missile strikes from Lebanese group Hezbollah in the Mediterranean and Yemen's Houthis in the Red Sea.
Earlier this week, the Israeli government's port authority issued a letter stating that terminals ranging from the southern port of Eilat on the Red Sea to the major Mediterranean ports in Haifa in northern Israel were operating at normal capacity.
But sirens sounded for the first time in months this week in the city of Haifa after missiles were fired by Hezbollah from Lebanon, and a drone launched by the Islamic Resistance in Iraq militia hit Eilat port, according to British maritime security company Ambrey.
In an advisory published on Friday that is closely watched by insurers and shipowners, Ambrey said it assessed the risk to vessels calling at Israeli ports to be "elevated".
"Possible further escalatory Israeli airstrikes or an Israeli ground incursion (in Lebanon) would highly likely cause direct operations against Haifa port," Ambrey said.
"Simultaneous action by Hamas, Houthi, or Iraqi militants place Israel’s remaining ports (Ashdod, Ashkelon, Hadera, Eilat) at continuous risk of collateral damage in singular long-range targeting operations."
The Iran-backed Houthis say they are acting in solidarity with Palestinians in Israel's war against Palestinian militant group Hamas in Gaza. In more than 70 attacks, the Houthis have sunk two vessels, seized another and killed at least three seafarers.
Shipping and insurance sources said ships calling at Israeli ports faced the broader threat of being targeted by Houthis in open waters in the Red Sea.
The world's top ship industry associations said in updated Red Sea guidance published on Friday that ship operators that have called or planned to call at Israeli ports "should limit information access".
"Published information could be used by Houthi forces as part of their targeting process," the advisory said. "Companies experiencing incidents on their ships should consider the likelihood the Houthis may target their ships in the future."
(Reuters - Reporting by Jonathan Saul, Editing by Timothy Heritage)