WASHINGTON — "I am coming to you. ... You will explode."

A recording of the voice and images of small boats buzzing around U.S. warships like gnats against elephants were shown in video released yesterday by the Pentagon.

But when Iranian fast boats swarmed two Hawai'i-based ships and another vessel from Washington, their confrontation Sunday in the Persian Gulf escalated toward a potentially deadly battle.

The Iranian boats appeared to ignore repeated warnings from the U.S. ships, including long, loud horn blasts and radio transmissions, as the ships moved through the Strait of Hormuz into the Gulf. And the Navy crews' verbal warnings grew more ominous.

In the four-minute, 20-second video, shot from the bridge of the Pearl Harbor-based destroyer USS Hopper, the small boats — including a bright blue one — can be seen racing near the wake the U.S. ships and crossing close to each other.

From the Hopper's bridge, after spotting the approaching Iranian boats, a Navy crew member says over the radio: "This is coalition warship. I am engaged in transit passage in accordance with international law. I intend no harm. Over."

Often uneven and shaky, the video condenses what Navy officials have said was a 20-minute or so clash early Sunday between three Navy warships and five Iranian fast boats. It ends with a blank screen, as only the audio of the Navy's final warning can be heard, just after the voice warns that they are coming.

"Inbound small craft: You are approaching a coalition warship operating in international waters. Your identity is not known; your intentions are unclear," the unidentified Navy crew member says.

He then cautions the Iranians that if they do not steer clear they will be "subject to defensive measures."

"Request that you alter course immediately to remain clear," the crew member says.

After a pause, the voice issues a final threat: "You will explode after (indecipherable) minutes."

A Navy crew member then repeated the threat as he heard it: "He says, 'You will explode after a few minutes.' "

At that point the tape ends.

President Bush yesterday denounced the incident as a "provocative act."

"It is a dangerous situation," Bush said during a White House news conference. "They should not have done it, pure and simple. ... I don't know what their thinking was, but I'm telling you what my thinking was. I think it was a provocative act."

The audio and video recordings were made separately but were pulled together by the Navy. Internal U.S. Navy transmissions can also be heard on the tape. The Hopper was in the lead, followed by the Pearl Harbor-based cruiser USS Port Royal and the frigate USS Ingraham from Everett, Wash.

The top Navy commander in the Gulf said the Iranian fleet of high-speed boats charged at and threatened to blow up the Navy convoy as it passed near — but outside — Iranian waters on Sunday. The Iranian fleet "maneuvered aggressively" and then fled as the American ship commanders were preparing to open fire, Vice Adm. Kevin Cosgriff said. No shots were fired.

In Tehran, Iran's Foreign Ministry suggested that the Iranian boats had not recognized the U.S. vessels. Spokesman Mohammed Ali Hosseini played down the incident.

"That is something normal that takes place every now and then for each party," he told the state news agency IRNA.