Iran Probing "Intentions" of U.K. Sailors

Updated at 5:58 a.m. Eastern.

Iran says it will take strong action against five British sailors detained by the Iranian navy after their racing yacht was stopped last week in the Persian Gulf if it is proven they had "bad intentions."

The British government says the yacht strayed inadvertently into Iranian waters while en route from Bahrain to Dubai to join a race.

The head of the Iranian president's office, Esfandiar Rahim Mashai, says that if it is proven that the sailors had "bad intentions" to violate Iran's security, "there will be a strong and serious attitude toward them," according to a report Tuesday in Iran's Fars news agency.

The detention could heighten tensions between Iran and major world powers, including Britain, that are demanding a halt to Tehran's controversial nuclear program.

Foreign Secretary David Miliband said Britain has been in touch about the case with Iranian counterparts and hoped the matter would be resolved soon. Speaking Tuesday to BBC, Miliband described the issue as a "purely consular matter."

"There's certainly no confrontation or argument," Miliband said. "As far as we are aware, these people are being well treated, which is right and what we would expect from a country like Iran."

"These are five civilians. They are yachtsmen. They were going about their sport," Miliband said. "It seems they may have strayed inadvertently into Iranian waters. We look forward to the Iranian government dealing with this promptly."

In Tehran, Foreign Ministry spokesman Ramin Mehmanparast said "the issue, whether it happened or not, and its details are under investigation."

"After clarification, the results of the investigation will be announced," the spokesman said.

The Fars agency said the British sailors were detained by the Revolutionary Guard but provided no attribution. Fars is considered close to the Guards.

"If the Britons were detained in the Persian Gulf, it is fully clear which force and from what country detained them," it quoted Guard navy chief, Gen. Ali Reza Tangsiri, as saying.

"Confronting foreign forces and their detention in the Persian Gulf is the task of the Guard," Tangsiri added.

Sail Bahrain's Web site identified the yacht as the "Kingdom of Bahrain" and said it had been due to join the 360-mile Dubai-Muscat Offshore Sailing Race, which was to begin Nov. 26. The event was to be the boat's first offshore race, the Web site said, adding that the vessel had been fitted with a satellite tracker.

It is not clear what route the boat took from Bahrain, which is just off the coast of Saudi Arabia, and Dubai, on the southeastern tip of the Arabian Peninsula. Richard Schofield, an expert on international boundaries in the Middle East at King's College in London, said it was difficult to understand how its crew could have ended up in trouble with Iranian authorities.

"It's hard to see why, on a regular journey from Bahrain to Dubai, they would have gone through Iranian territorial waters," he said.

British media identified the five as Oliver Smith, Sam Usher, Luke Porter, Oliver Young, and David Bloomer.

The detention of the British would not be the first of foreign nationals by Tehran.

Iran is holding three young Americans who strayed across the border from northern Iraq in July. The U.S. has appealed for their release, saying they were innocent hikers who accidentally crossed into Iran. Tehran has accused them of spying, a sign that they could be put on trial.

Fifteen British military personnel were detained in the Gulf by Iran under disputed circumstances in March 2007. Iran charged them with trespassing in its waters, and the Iranian government televised apologies by some of the captured crew.

All were eventually freed without an apology from Britain, which steadfastly insisted the crew members were taken in Iraqi waters, where they were authorized to be.