US Navy ships in the Arabian Sea intercepted and seized an arms shipment from Iran likely bound for Houthi militias in Yemen, the military said in a statement on Monday. The weapons seized last week by the warships Sirocco and Gravely were hidden on a small dhow and included 1,500 AK-47 rifles, 200 rocket-propelled grenade (RPG) launchers, and 21 .50-caliber machine guns, according to the Navy statement. The weapons were seized on March 28 and are now in US custody. The boat, which the Navy described as stateless, and its crew were allowed to leave once the weapons were taken. "This seizure is the latest in a string of illicit weapons shipments assessed by the US to have originated in Iran that were seized in the region by naval forces," the military said in the statement. It cited a Feb. 27 incident in which the Australian Navy intercepted a dhow in late February and confiscated nearly 2,000 AK-47s, 100 RPG launchers, and other weapons. On March 20, a French destroyer seized almost 2,000 AK-47s, dozens of Dragunov sniper rifles, nine antitank missiles, and other equipment. Houthi militias seized Yemen's capital Sanaa in 2014, stoking concern in Saudi Arabia that Iran was exploiting turmoil in the region and extending its influence to the Saudi border. The Houthis, whose home territory is in northern Yemen, practice Shiite Islam, the majority faith in Iran. White House spokesman Josh Earnest said on Monday that Iran's support for the Houthis is an example of its "destabilizing activities" in the region, and that the weapons shipment could be raised at the United Nations Security Council. "We obviously are concerned about this development, because offering up support to the rebels in Yemen is something that is not at all consistent with UN Security Council resolutions," Earnest said. US officials have said in the past that Iran's direct involvement with the Houthis is limited, but that Iranian military personnel were training and equipping Houthi units. A Saudi-led Arab coalition has been fighting to restore Yemen's President Abdrabbu Mansour Hadi to power since last year, including via air strikes on Sanaa. UN-sponsored peace talks are scheduled to start in Kuwait on April 18. The two sides have confirmed a truce starting at midnight on April 10 ahead of the peace talks, scheduled to follow a week later.