An Iranian drone buzzed an American carrier in the Gulf and came dangerously close to aircraft for the second time in a week, the US Navy has said.

The unnamed Iranian QOM-1 aircraft risked collision when it came within 1,000ft of planes flying from USS Nimitz on Sunday.

A US Navy statement criticised the remote-controlled flight as "unsafe and unprofessional" and said it "created a dangerous situation with the potential for collision".

Last week a drone flew within 100ft of one of the carrier’s F/A-18E Super Hornet jets as it waited to land. The plane had to take evasive action to avoid a collision.

Lt Ian McConnaughey said in the latest encounter the Iranian aircraft was flying at dusk without navigation lights.

He told AFP: “Despite repeated radio calls to establish communications and remain clear, the QOM-1's controlling station was unresponsive and the [drone] did not use any aircraft navigation lights while it made several passes in close proximity to Nimitz and its escort ships during active flight operations, coming within 1,000 feet of US aircraft."

He said drones of several nations regularly came to observe warships in the Gulf, but the two recent incidents had been particularly close and dangerous.