Tehran: Iran released a video on Thursday which it said showed its boats did not threaten US navy vessels in the Gulf on Sunday.

The video aired by Iran's Press TV showed an Iranian naval officer in a small craft speaking via radio to a ship which could not be clearly identified.

Guards Brigadier General Ali Fadavi said the Iranian boats had only approached the US ships in the Strait of Hormuz to examine their registration numbers, Press TV said.

"Coalition warship 73 this (is an) Iranian navy patrol boat," the officer said in accented English in the video tape.

"This is coalition warship 73. I read you loud and clear," the person replied in American accent. The Iranian officer then asked for the ship to identify itself.

Pentagon earlier released its own video, which included a voice from a US ship telling one of the small craft that it was "straying into danger and may be subject to defensive measures".

The craft responded: "You will explode after ... minutes," according to the video.

The incident was the latest sign of tension between America and Iran. America's George W. Bush warned Iran on Wednesday of "serious consequences" if it attacked US ships in the Gulf again.