A British-owned, Japanese-operated cargo ship has been seized in the Red Sea by the Iran-backed Houthi armed group, the Israeli military and other sources said Sunday.

The Japanese government confirmed that the cargo ship operated by Nippon Yusen K.K., more widely known as NYK Line, had been seized and said there were no Japanese citizens among its crew.

The government "decisively condemns such an act," Japan's top spokesman Hirokazu Matsuno said Monday in Tokyo, adding it is working with relevant countries to secure the release of the ship and crew.

The Galaxy Leader is seen at the port of Koper in Slovenia in September 2008. (Kristijan Bracun/AP/Kyodo)

Iran has denied involvement in the seizure, with a Foreign Ministry spokesperson telling a press conference on Monday that resistance groups in the region act "independently."

Nippon Yusen set up an emergency task force at its headquarters in Tokyo. The company said it has been unable to contact the car-carrying ship, named the Galaxy Leader, which has no cargo on board.

The company also said it has been sharing information with the British company that owns the vessel. "We are handling the situation with the safety of crew members as the top priority."

The Houthis said in a statement that they captured an "Israeli ship" and sailed it to Yemen.

The Houthis insisted the seizure of the vessel was done on behalf of the Palestinians, who they said are being massacred by Israel. They said they will target all ships related to Israel and warned that no country's vessels should engage with Israel in the Red Sea.

The Israeli prime minister's office said, "Israel strongly condemns the Iranian attack against an international vessel."

"The ship, which is owned by a British company and is operated by a Japanese firm, was hijacked with Iran guidance by the Yemenite Houthi militia," it said, adding that no Israelis are aboard the ship.

Israeli media reported that the vessel is registered under the British firm, which is partially owned by Israeli tycoon Abraham Ungar.

A total of 25 people were on board, with crew members from Bulgaria, Mexico, the Philippines and Ukraine, according to the Israeli prime minister's office.

The Israel Defense Forces said, "The hijacking of a cargo ship by the Houthis near Yemen in the southern Red Sea is a very grave incident of global consequence."

The military said the ship is not Israeli, noting that the vessel departed Turkey bound for India.

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