Blair warns Tehran of 'different phase' if 15 sailors are not freed

London & Tehran: Britain's Prime Minister Tony Blair warned Tehran on Tuesday of a "different phase" if it did not free 15 British sailors captured four days ago.

Iran says it may charge the 15 sailors and marines with illegally entering its waters. Britain insists the two boatloads of sailors were in Iraqi waters in the northern Gulf and has demanded their immediate release.

"What we are trying to do ... is to pursue this through the diplomatic channels and make the Iranian government understand these people have to be released and that there is absolutely no justification whatever for holding them," Blair said.

"And I hope we manage to get them to realize they have to release them. If not, then this will move into a different phase," he told GMTV.

Asked what he meant by a "different phase," Blair said: "Well, we will just have to see, but what they should understand is that we cannot have a situation where our servicemen and women are seized when actually they are in Iraqi waters under a UN. mandate, patrolling perfectly rightly and in accordance with that mandate, and then effectively captured and taken to Iran."

The sailors' capture on Friday heightened tensions between Iran and the West just a day before the U.N. Security Council imposed new sanctions on Iran over its disputed atomic program.

British officials have been assured that the sailors are well but have not been given access to them or told where they are being held.

Britain asked Russia, which has close diplomatic and trade ties with Tehran, and other states to help secure their release.

It also summoned Iran's ambassador in London, Rasoul Movahedian, for the third time since the crisis began. Foreign Office Minister David Triesman had "a frank and clinical discussion" with him, the Foreign Office said.

"Lord Triesman underlined the seriousness of the situation and repeated the government's demands about the whereabouts of our personnel, the embassy's request for consular access and that they should be released immediately," the office said.

Iran has said it is considering charging the Britons with illegally entering its waters. Vice Foreign Minister Mahdi Mostafavi said on Monday they were being interrogated to see if they had crossed into Iranian territory on purpose or not.

"When that is clear the appropriate decision will be made," Iranian state television cited Mostafavi as saying.

Britain's ambassador to Tehran asked to see a senior Iranian Foreign Ministry official for details of the 15 and to be allowed to see them, the Foreign Office said.

The official "assured him the group were fit and well and in Iran. He gave no further details at this stage," it said.

Iraq also urged Iran to free the Britons, saying they were detained in its waters, as London says.

Iran's Foreign Minister Manouchehr Mottaki said in New York on Sunday that the charge against the British sailors arrested in Iran is illegal entry into Iranian waters and that the issue is being examined legally.

Talking to reporters at the United Nations in New York, he added that the British charge d'affaires in Tehran was summoned to the Foreign Ministry to be informed of Tehran's protest regarding the illegal entry of British forces into the Iranian territory.

"Iranian authorities detained the sailors in Iranian waters. This issue is not unprecedented and is being examined legally," Mottaki said.

The family of one of the captured sailors - named in the British media as Faye Turney, 26, the only woman in the group - voiced their distress. "While we understand the media interest in the ongoing incident involving Faye, this remains a very distressing time for us and our family," a statement, issued on the family's behalf by the Ministry of Defense, said.