US:Tensions between the US and Iran resurfaced yesterday when Pentagon officials alleged that Iranian warships had threatened three US navy vessels in the Strait of Hormuz.
The alleged incident comes after a period of relative calm in relations between the two countries, and ahead of a rare visit to Iran by the head of the International Atomic Energy Agency (IAEA), Mohamed ElBaradei.
According to Pentagon officials, US forces were about to fire at the Revolutionary Guard boats when the Iranians turned away.
White House spokesman Tony Fratto said: "We urge the Iranians to refrain from such provocative actions that could lead to a dangerous incident in the future."
The Iranian foreign ministry dismissed the confrontation as "something normal" that was resolved without incident.
Pentagon officials said the incident occurred early on Sunday as a US frigate, destroyer and cruiser passed through the strategic oil route. Five small boats, thought to be from the Revolutionary Guard, began passing in front of the US vessels, dropping boxes in the water to force the Americans to take evasive action.
Describing the confrontation as "significant", a Pentagon official said the Iranians had radioed the US ships with a message to the effect that "we're coming at you and you'll explode in a couple of minutes". The Iranians moved away "literally at the very moment that US forces were preparing to open fire . . . It is the most serious provocation of this sort that we've seen yet", the official added.
A US defence department spokesman said the Iranian boats were operating at "distances and speeds that showed . . . reckless, dangerous and potentially hostile intent.
"At least some were visibly armed. Small Iranian fast boats made some aggressive manoeuvres against our vessels and indicated some hostile intent."
The allegation echoes an incident in March last year when Revolutionary Guards held 15 British sailors for nearly two weeks after alleging that they had strayed into Iranian waters.
A US state department spokesman said there were no plans to lodge a formal protest. "Without specific reference to this incident in the Strait of Hormuz, the United States will confront Iranian behaviour where it seeks to do harm either to us or to our friends and allies in the region. There is wide support for that within the region and certainly that's not going to change."
Relations between the US and Iran have been fraught in recent years, with Washington voicing concern over Iran's nuclear programme and the role of the Revolutionary Guard in fomenting unrest in neighbouring Iraq.
Iran is under two sets of UN sanctions for its refusal to freeze uranium enrichment.
However, a recent US intelligence assessment concluded that Iran shut down its clandestine nuclear weapons programme in 2003.
In May last year US ambassador Ryan Crocker met his Iranian counterpart, breaking a 27-year diplomatic freeze between the countries.
This week, Mr ElBaradei will go to Tehran at the invitation of the Iranian government. His office said the trip was intended to enable the IAEA develop ways to "enhance and accelerate" nuclear safeguards in Iran.