Yemen confirmed on Saturday a ship intercepted last month off its coast was an Iranian vessel trying to smuggle explosives and surface-to-air missiles to the country, the state news agency Saba reported.
Officials in Washington said earlier this week that the seizure of the ship on January 23 had been coordinated with the U.S. Navy and the intercepted shipment was believed to have been from Iran and destined for insurgents, likely to be Shi'ite Muslim Houthi rebels mainly based in northern Yemen.
Saba quoted a source at Yemen's higher security committee as saying the weapons including Russian-designed SAM 2 and SAM 3 anti-aircraft missiles, were hidden inside four containers concealed by a diesel tank with a capacity of 100,000 litres.
"The source said that the ship, with its cargo, was handed over to eight Yemeni crew memebers in Iran to then deliver it to Yemeni shores," Saba said. The agency said the weapons were now being unloaded, sorted and the crew questioned.
"The results will be published after the contents of the ship are unloaded and sorted," it added.
Gulf Arab governments and Sunni clerical allies accuse Tehran of backing co-religionist communities around the region, and Sanaa has also accused the Islamic republic of trying to meddle in Yemeni affairs.
Yemen's President Abd-Rabbu Mansour Hadi snubbed a visiting Iranian envoy last year to signal "displeasure" after Sanaa said it uncovered an Iranian-led spy ring in the capital.
A U.S. official, who spoke on condition of anonymity, said on Monday that the seizure of the ship demonstrates "ever pernicious Iranian meddling in other countries in the region".
Iran denies any interference in Yemen's affairs.
Analysts and diplomats believe the Houthis, named after their leaders' family, have turned Yemen into a new front in a long struggle between Iran, Western powers and the Arab regimes they support.
Earlier in January, the U.S. envoy to Yemen, Gerald Feierstein, was quoted as accusing Iran of working with southern secessionists seeking to restore the country that merged with North Yemen in 1990.
Yemen is also grappling with an al Qaeda insurgency in the centre and south of the country. Its location flanking top oil producer Saudi Arabia - Iran's regional adversary - and major shipping lanes have made restoring its stability an international priority.
Yemen's government said in a statement issued by the Yemeni embassy in Washington last Monday that the shipment was intercepted in Yemeni waters, close to the Arabian Sea.
It said Yemeni Coast Guard officials boarded the vessel, which flew multiple flags and had eight Yemeni crew members on board.
"Authorities are continuing to investigate the vessel's shipping route by analysing navigation records found on board the ship," the statement said.