Iranian Revolutionary Guards have downed several Western spy drones, including two over the Strait of Hormuz, also known as the Persian Gulf, according to claims by the Islamic Republic’s semi-official media. U.S. officials say they know of no such attacks.

Iran's Brigadier-General Amir Ali Hajizadeh, head of the Guards’ air force branch, told the Fars News Agency, “They [Westerners] have made limited aggressions against the country and we have shot down a number of their highly advanced spy planes so far. For example, we have brought down two spy planes over the Persian Gulf. Westerners have a series of capabilities which cannot be ignored, especially satellites, or for example they have spy planes which can take pictures in some places.”

He did not mention where and when the alleged anti-reconnaissance operations took place. He added that most of the drones are used in Iraq and Afghanistan, but that there are “some violations against our soil." The United States, whose navy patrols the Gulf’s international waters, has not confirmed the claim.

CNN reported that one U.S. official said, "We have no recent reports of any losses of UAVs [unmanned aerial vehicles] in the Gulf due to any cause. And while we have lost them in the past, I am not aware of any indication that those had been due to hostile fire of any kind."

Hajizadeh said in an interview published on Sunday, “We have constant clashes with the enemy’s surveillance and reconnaissance aircrafts. Our missile bases are spread out across the country, and these missiles have been deployed in a way that if the enemy clashes with us, the number of the missiles we fire at them will increase day by day.”

The Guards also claimed that they used the downed drones as a source for producing them for Iranian use.

The U.S. Navy’s Fifth Fleet is based across the Gulf, and Iran previously has threatened to block the waters if it is attacked. More than half of the world’s oil flows passes through the Gulf in tankers.

Two years ago, an Iranian legislator claimed that the Guards downed a U.S. spy drone, and last May, an Iranian army general said the air force had chased way a reconnaissance plane.