Iran's Revolutionary Guards said on Sunday that they seized an American submarine drone in the strategic Strait of Hormuz, which Tehran has blockaded in the months-long Middle East war.

"Through a coordinated, complex operation involving intelligence oversight and electronic warfare, IRGC naval forces' personnel successfully captured an advanced unmanned underwater vehicle (UUV) belonging to the terrorist US military," the IRGC naval forces said in a statement, according to state TV.

They added that the drone was "operating in the Strait of Hormuz for espionage purposes", identifying the model as a Remus 600 autonomous underwater vehicle that was "now in the hands of the force's specialists for data recovery".

Earlier this month, the Guards said they captured another US submarine drone in the strait that was crucial for oil and gas trade before the Middle East war started in late February and choked off shipping.

Iran has maintained a blockade of the Hormuz strait since the outbreak of the conflict, while the United States has imposed a counter-blockade of Iranian ports.