Iran said today it was interrogating eight British naval personnel, who were shown in blindfolds on Iranian television a day after they were captured aboard three small boats in the disputed Shatt al Arab waterway that separates Iran from Iraq.

But there were conflicting reports on what Iran intends to do with the men following a report on an Iranian state television channel that they would be tried on charges of illegally entering Iranian waters.

"Interrogations to find out the reason those people entered Iran's waters are going on, and no other issue is under discussion now," the Reuters news agency quoted an Iranian Foreign Ministry source as saying in Tehran. The agency said the source contradicted the report in which the Iranian Arabic-language news channel al Alam, citing unidentified Iranian military sources, said the British captives would be prosecuted on charges of "illegally entering Iran's waters."

Al Alam said the vessels intruded more than half a mile inside Iranian territory and that the British crew members "confessed" that they were in Iranian waters when they were arrested.

A naval official of the hard-line Revolutionary Guards backed the report, telling the semi-official Fars News Agency that the British were carrying sophisticated weapons and maps and would be prosecuted.

"Their case will go through normal legal procedures, and these people will be handed over to the judiciary," the agency quoted the unidentified official as saying. The official reportedly said the men "were fully armed" with "advanced rifles, night vision systems and other types of equipment," in addition to their "personal arms."

A more conciliatory approach was expressed by Ali Reza Afshar, a senior Iranian military official who held out the prospect that the British could be freed soon.

"If the result of the interrogations of those British military men shows that they didn't have any bad intention, they will be released soon," Afshar told the Iranian Students' New Agency, Reuters reported.

The conflicting reports suggested that the captured men may have been drawn into Iran's long-running power struggle between hard-liners loyal to the country's ruling Islamic clerics and officials of the more moderate government of President Mohammad Khatami.

The British were initially shown on al Alam television sitting silently on chairs and a sofa in an unidentified location, three of them in British military uniforms and the five others wearing military trousers and civilian T-shirts.

But footage broadcast later by the channel showed them blindfolded and sitting cross-legged on the floor.

In London, the British Foreign Office said it had no confirmation that Iran intended to try the men.

"We're not entirely sure" what the Iranians plan to do with the eight crew members, said Simon Shercliff, a spokesman for the Foreign Office.

The crew members were in three small river craft that were seized Monday as one of the boats was being delivered to the Iraqi Riverine Patrol Service.

Shercliff said that while the boats "obviously went close to the line," it was not certain that they had crossed it.

Al Alam reported that the British boats contained weapons, cameras and detailed maps of Iraq and Iran, suggesting that they were spies.

The British Defense Ministry said the eight personnel from the Royal Navy training team in southern Iraq were traveling in three boats -- two small craft called Boston Whalers that hold about a half a dozen people -- and one British Army combat support boat. They were taking one of the boats from Umm Qasr to Basra for delivery to the Iraqis as part of a training mission, Shercliff said.

"The boats were unarmed, but the crews were carrying their personal weapons," the Defense Ministry said.

The Royal Navy training team is made up of more than 30 Royal Navy and Royal Marines personnel and operates along 228 miles of internal waterways in Basra Province while training the Iraqi Riverine Patrol Service to combat smuggling and terrorism, according to the Defense Ministry.

To seek the men's release, British Foreign Secretary Jack Straw spoke this morning to the Iranian foreign minister, Kamal Kharrazi, the Foreign Office said. In addition, the Iranian ambassador in London, Morteza Sarmadi, was called in for a meeting at the Foreign Office.

"The ambassador was asked to explain why the eight are being held, for their release as soon as possible and for full consular access to them meanwhile," the Foreign Office said in a statement. "He was asked for information on the reports that they will be prosecuted and told they were on a routine mission."

Shercliff said British authorities were awaiting a response from the Iranians.