Iran said Monday it was interrogating 15 British sailors and marines to determine if their alleged entry into Iranian waters was "intentional or unintentional" before deciding what to do with them - a first, tentative sign it could be seeking a way out of the standoff. The two countries continued to disagree about whether the sailors were in Iranian waters when they were captured, with Britain categorically saying they were not and Iran saying it has proof that they were. So far it has been impossible to independently confirm where the sailors were, but the British Defense Ministry said they were seized in the Shatt al-Arab, the waterway flowing into the Gulf that marks the border between Iran and Iraq. But the exact path of the border in the waterway, known in Iran as the Arvand river, has long been disputed. The Iranian emphasis on the sailors' intent Monday was a noticeable deescalation from the certainty expressed Saturday by Iran's military chief, Gen. Ali Reza Afshar. Afshar had said the 15 sailors had "confessed" to "aggression into the Islamic Republic of Iran's waters." Other Iranian officials suggested afterward that the 15 might be charged with a crime - presumably espionage or trespassing - for knowingly entering Iranian territorial waters. But Deputy Foreign Minister Mehzi Mostafavi said Monday that the 15 - 14 men and one woman - were still being interrogated. "It should become clear whether their entry was intentional or unintentional. After that is clarified, the necessary decision will be made," Mostafavi said. Iran has refused to give an indication of the sailors' whereabouts or to allow British officials to speak with them, but assured the British ambassador to Teheran, Geoffrey Adams, that they were in good health. There were fears in Britain that the fate of the 15 could get caught up in the political tensions between Teheran and the West, including the dispute over Iran's nuclear program and accusations of Iranian help to Shiite militants in Iraq. In particular, there were worries Iran might seek to exchange the Britons for Iranians detained by US forces in Iraq. Mostafavi denied Iran was seeking a trade, but there were powerful calls within Iran's leadership for the government to hold out for a swap. A Web site run by Mohsen Rezaei, secretary of the influential Expediency Council and a former Revolutionary Guard commander, quoted an unidentified lawmaker saying, "If Iranian diplomats in Iraq have no security, there's no reason why we should forgive and turn a blind eye to aggressors into Iranian territories." Some members of the Iranian public also called for the British to be held and tried, with Iranian students turning out by the hundreds near the coast where the sailors were seized to urge an escalation in the confrontation with the West. Britain sought to play down fears the situation could escalate and become intertwined with the nuclear and Iraq disputes. "This is a matter that should be dealt with on its own merits," British Prime Minister Tony Blair's official spokesman said. The seizure of the crew was an issue to "be treated on its own, and that is how we are approaching it." Blair said Sunday he hoped the situation could be resolved in as diplomatic a way as possible, and his office stressed the British leader had been "very careful when he intervened," mindful of the potential repercussions on other issues. Iran's ambassador to Iraq, Hassan Kazemi Qomi, told The Associated Press in a telephone interview from Baghdad that there was no connection between the capture of the sailors and other disputes between the West and Iran. "They entered Iranian territorial waters and were arrested," Qomi said. "It has nothing to do with other issues." Mostafavi, the deputy foreign minister, also denied Iran was aiming for a prisoner swap.