The United States has lodged a formal diplomatic protest with Iran over a weekend incident in which Iranian speedboats harassed US warships in the Persian Gulf's Hormuz Strait, the State Department said Thursday. The protest, which reiterates earlier US complaints about the "provocative" action, was sent to the Iranian Foreign Ministry through the Swiss Embassy in Tehran, which looks after US interests in Iran, deputy spokesman Tom Casey told reporters. He could not say whether the Iranians had received and acknowledged receipt of the protest "We have ... prepared and given to the Swiss a diplomatic note formally protesting this incident," Casey said. "It reiterates the points that we have made publicly in the last few days." Casey said: "We certainly don't want to see the Iranians taking any kind of provocative actions or provocative steps against our ships or against any ships that are transiting what is a primary international waterway," Casey said. He dismissed Iranian claims that nothing was unusual about Sunday's incident in the Strait of Hormuz as well as a videotape aired by Iranian television on Thursday that appeared to have been an attempt to show that there was not a confrontation between vessels of the two countries. "We all understand what happened in this incident," Casey said. The US Defense Department maintains that Iranian naval speedboats swarmed around US warships in a threatening manner. The Pentagon released its own video of the incident, in which a man says in accented English: "I am coming to you. ... You will explode after ... minutes." President George W. Bush has warned Iran not to repeat such actions, which he said would draw "serious consequences." Iran denies its boats threatened the US vessels and accused Washington of fabricating its video. The Pentagon has dismissed that claim and warned its ships would respond with force if threatened. The grainy 5-minute, 20-second Iranian video shows a man speaking into a handheld radio, with three US ships floating in the distance. It appeared to be shot from a small boat bobbing at least 100 yards from the American warships. The footage does not show any Iranian boats approaching the US vessels or any provocation. The incident lasted about 20 minutes, according to the US Navy, and a Pentagon official said that while the Iranian video appeared to have been taken around the time of the confrontation, controversial parts had been edited out. The clip aired on Iran's state-run English-language channel Press TV, whose signal often is blocked inside Iran. It also aired on the state-run Al-Alam Arabic channel, with an announcer saying the video showed "a routine and regular measure." The incident, which ended without any shots fired, has heightened US-Iranian tension as Bush visits the region. Bush was in the West Bank on Thursday and heads next to Arab nations on the other side of the Persian Gulf from Iraq, where he is expected to discuss strategy on Iran.