SANAA - Yemeni coast guard in coordination with the US navy stopped a ship last week in the Arabian sea loaded with rockets and explosives, the interior ministry said on Tuesday.
US officials suspect the weapons were being smuggled from Iran and destined for Yemeni insurgents.
The coast guard boarded the vessel, operated by Yemeni crew, in the territorial waters of the south Arabian Peninsula country and found on it a cache of weapons, including shoulder-fired surface-to-air missiles and rocket-propelled-grenades, the ministry said in a statement carried by state news agency Saba.
It said the weapons also included bomb making equipment and other explosives.
The ministry said the authorities were still questioning the crew to establish the source and destination of the arms, pointing out that the ship was flying several fake flags.
A US official, speaking on condition of anonymity, confirmed the operation was coordinated with the US Navy and that a Navy destroyer was nearby.
A second official said the intercepted shipment was believed to have been from Iran and destined for insurgents, likely Huthis.
"This demonstrates the ever pernicious Iranian meddling in other countries in the region," said the second U.S. official, who also spoke on condition of anonymity.
Iran denies any interference in Yemen's affairs.
Analysts and diplomats believe that the ascent of the Huthis, named after their leaders' family, has turned Yemen into a new front in a long struggle between Iran and Western powers and the Arab regimes they support.
Gulf Arab governments and Sunni clerical allies accuse Iran of backing Shiite communities around the region, and Sanaa has also accused Iran of trying to meddle in Yemeni affairs.
Yemen's President Abd-Rabbu Mansour Hadi snubbed a visiting Iranian envoy last year to signal "displeasure" with Tehran after Sanaa said it had uncovered an Iranian-led spy ring in the capital.
Earlier this month, the US envoy to Yemen, Gerald Feierstein, was quoted accusing Iran of working with southern secessionists. Yemen is also grappling with al Qaeda militants in the north.
Yemen, an impoverished country, is awash with weapons where powerful tribes are heavily armed, and carrying personal arms is part of the tradition.
The country is also home to Al-Qaeda in the Arabian Peninsula, seen as the most dangerous branch of the jihadist network.
The US Navy operates in the Arabian Sea and the Gulf of Aden as part of the international force patrolling the area to combat maritime piracy.