(CNN)A joint US Navy and Coast Guard team seized thousands of illicit weapons last week after stopping a small ship in the North Arabian Sea, the Navy said in a statement.
The cruiser USS Monterey stopped the stateless dhow on May 6 during a routine operation to verify its registry, the Navy said.
A US Coast Guard Advanced Interdiction Team deployed on the Navy ship then boarded the dhow and found the weapons stash.
The massive arms haul covered much of the rear flight deck of the 567-foot (173-meter) US warship after it was transferred over in what the Navy said was a two-day operation.
"The cache of weapons included dozens of advanced Russian-made anti-tank guided missiles, thousands of Chinese Type 56 assault rifles, and hundreds of PKM machine guns, sniper rifles and rocket-propelled grenade launchers. Other weapon components included advanced optical sights," the Navy statement said.
The origin and destination of the weapons is under investigation but previous arms shipments confiscated by the US Navy under similar circumstances were bound for Houthi rebels in Yemen, Lt. Cmdr. Pete Pagano, a spokesperson for the Navy's Fifth Fleet told CNN in an email Monday.
Pagano cited three similar seizures by the Fifth Fleet in recent years.
On February 12, the guided-missile destroyer USS Winston Churchill stopped two dhows off the coast of Somali, which were carrying weapons including rocket-propelled grenade launchers, crew-served weapons and small arms.
On February 9, 2020, the cruiser USS Normandy stopped a dhow in the Arabian Sea and seized missile components.
And on November 25, 2019, the destroyer USS Forrest Sherman found missile components on a dhow it stopped in the Arabian Sea.
The Navy also said the weapons seized last week will remain in US custody while the investigation is ongoing.
After the dhow stopped last week was deemed seaworthy and its crew was questioned, they were provided with food and water and released, according to the statement.