A US Navy ship has opened fire on a small boat racing toward it near the Gulf city of Dubai, killing one person, according to American officials.
Lieutenant Greg Raelson, a spokesman for the Navy's Bahrain-based 5th Fleet, said a security team aboard the USNS Rappahannock issued a series of warnings before resorting to lethal force near Dubai's Jebel Ali port.
"The US crew repeatedly attempted to warn the vessel's operators to turn away from their deliberate approach. When those efforts failed to deter the approaching vessel, the security team on the Rappahannock fired rounds from a .50-calibre machine gun," he said in an emailed response to questions.
Raelson said the incident is under investigation.
The Rappahannock is an oiler used to fuel other Navy ships while they are at sea.
The United Arab Emirates, which includes the commercial hub of Dubai and the oil-rich capital Abu Dhabi, is a key American ally in the Gulf. American warships frequently visit Dubai's Jebel Ali port, a popular rest stop among US sailors.
A US consular official said that one person was killed and three wounded in the shooting.
The official gave no other details, but it appeared that US personnel could have seen the boat — mistakenly or not — as a threat in Gulf waters not far from Iran's maritime boundaries.
The white-hulled boat was inspected by dozens of police and other Emirati officials after the incident in a small Dubai port used by fishermen and sailors.
The boat appeared to be a civilian vessel about nine metres long and powered by three outboard motors. It had no obvious military markings.
Similar boats are used for fishing in the region, though Iran's Revolutionary Guard also employs relatively small, fast-moving craft in the Gulf.
Rescue workers were seen carrying one person in a body bag off the boat and placing it in an ambulance as fishermen looked on. Officials moved the boat from the harbor shortly afterward.
An Emirati rescue official at the scene confirmed the casualty toll.
Another UAE official familiar with the incident said authorities "are looking into the matter and will be issuing a report at a later stage."
Like the US consular official, they spoke on condition of anonymity because of the sensitivity of the incident between the two allies.
US military vessels routinely cross paths with Iranian ships in international waters in the Gulf without incident, but speed boats from Iran's Revolutionary Guard have passed close to US ships in incidents that have raised alarm in Washington.
In early 2008, then President Bush accused Iran of a "provocative act" after five small Iranian craft buzzed around the destroyer USS Hopper.
Tensions are elevated in the Gulf after Iran last week renewed threats to close the strategic Strait of Hormuz — the route for one-fifth of the world's oil — in retaliation for tighter sanctions over Iran's nuclear program. The US recently boosted its naval presence in the Gulf with additional minesweepers and other warships.
The US Embassy in Abu Dhabi had no immediate comment, referring all questions to the Navy.