Dubai: An Iranian vessel with 19 sailors on board has been seized near a Yemeni island by local fishermen, Yemen’s prime minister said on Saturday.

There was no immediate official Iranian reaction to the comments made by Ahmad Obaid Bin Dagher on his Twitter account in which he said the ship was detained off the coast of Socotra, the largest island in an archipelago south of Yemen.

He thanked the fishermen of another island in the archipelago, Abd Al Kuri, which lies to the east of Somalia.

Regional and Western sources have said that Iran is sending advanced weapons and military advisers to Yemen’s rebel Al Houthi movement, stepping up support for its Shiite ally in the country’s civil war.

In September, a top US admiral in the Middle East said Iran continues to smuggle illicit weapons and technology into Yemen, stoking the civil strife there and enabling Iranian-backed rebels to fire missiles into neighbouring Saudi Arabia that are more precise and far-reaching.

The officer, Vice-Admiral Kevin M. Donegan, said that Iran was sustaining Al Houthis with an increasingly potent arsenal of anti-ship and ballistic missiles, deadly sea mines and even explosive boats that have attacked allied ships in the Red Sea or Saudi territory across Yemen’s northern border.

The US, the Yemeni government and their allies in the region have retaliated with strikes of their own and recaptured some Al Houthi-held coastal areas to help blunt threats to international shipping, but the peril persists, the admiral said.

“These types of weapons did not exist in Yemen before the conflict,” said Donegan. “It’s not rocket science to conclude that Al Houthis are getting not only these systems but likely training and advice and assistance in how to use them.”

The admiral’s charges appear supported, at least in part, by findings in a report late last year by Conflict Armament Research, a private arms consultancy.

The report concluded that the available evidence pointed to an apparent “weapon pipeline, extending from Iran to Somalia and Yemen, which involves the transfer, by dhow, of significant quantities of Iranian-manufactured weapons and weapons that plausibly derive from Iranian stockpiles.”

For years, Iran has been under a series of international sanctions prohibiting it from exporting arms.

The US has frequently claimed that Tehran has violated the sanctions in support of proxy forces in many conflicts, including in Iraq, Syria, Yemen and the Palestinian territories.

Between September 2015 through March 2016, allied warships interdicted four Iranian dhows that yielded, in total, more than 80 anti-tank guided missiles and 5,000 Kalashnikov rifles as well as sniper rifles, machine guns and almost 300 rocket-propelled grenade launchers, according to data provided by the US Navy.

Donegan said that while there have been no seizures since, he said he suspects Iran’s hand in Al Houthis’ apparent ability to replenish and improve their arms stockpiles. “It is not something that was a one-time deal and stopped,” Donegan said. “It appears to be progressive.”