Unidentified armed individuals have seized a tanker carrying a cargo of phosphoric acid in the Gulf of Aden on Sunday, the vessel’s managing company and a U.S. defence official said.

The incident, involving the chemical tanker Central Park, is the latest in a series of attacks in Middle Eastern waters since a brutal war between Israel and the Palestinian militant group Hamas broke out on Oct. 7.

It followed a seizure of an Israeli-linked cargo ship by Yemen Houthis, allies of Iran, in the southern Red Sea last week. The group, which also fired ballistic missiles and armed drones at Israel, vowed to target more Israeli vessels.

“U.S. and coalition forces are in the vicinity and we are closely monitoring the situation,” the U.S. official said.

Central Park, a small chemical tanker (19,998 metric tons), is managed by Zodiac Maritime Ltd, a London-headquartered international ship management company owned by Israel’s Ofer family. The Liberian-flagged vessel was built in 2015 and isowned by Clumvez Shipping Inc, LSEG data showed.

Zodiac Maritime said in a statement Central Park, which is carrying a full cargo of phosphoric acid, was involved in a suspected piracy incident while crossing international waters, approximately 54 nautical miles off the coast of Somalia.

Phosphoric acid is mostly used for fertilisers.

“Our priority is the safety of our 22 crew onboard. The Turkish captained vessel has a multinational crew consisting of a crew of Russian, Vietnamese, Bulgarian, Indian, Georgian and Filipino nationals,” the statement added.

There was no immediate comment from Houthi officials.

Britain’s Maritime Trade Operations agency (UKMTO) said on Sunday it was aware of a possible attack in southwest Aden and called on other vessels to exercise caution.

The U.S. has blamed Iran for unclaimed attacks on several vessels in the region in the past few years. Tehran has denied involvement.

A container ship managed by an Israeli-controlled company was hit by a suspected Iranian drone in the Indian Ocean, causing minor damage to the vessel but no injuries, a U.S. defence official said on Saturday.

Hamas fighters rampaged into Israel on Oct. 7, killing 1,200 people. Since then, Israel has rained bombs on Gaza, killing about 14,000 people, roughly 40% of them children, Palestinian health authorities say.

Thirteen Israelis and four Thai nationals arrived in Israel early on Sunday after a second release of hostages held by Hamas following an initial delay caused by a dispute about aid delivery into Gaza.

Source: Reuters reported by Aziz El Yaakoubi, additional reporting by William Schomberg in London and edited by David Goodman and Louise Heavens