KEY POINTS:
LONDON - Britain's Prime Minister Tony Blair warned Tehran today of a "different phase" if it did not free 15 British military personnel captured in the Gulf four days ago.
The sailors' capture and new UN sanctions imposed on Tehran on Sunday over its disputed nuclear programme have stoked tensions between the West and Iran and pushed oil prices to a 2007 high.
Russia and the United Arab Emirates today urged Iran to comply with UN demands that it halt sensitive nuclear work but Tehran says the UN resolution is illegal.
Iran, which denies any intention of making atomic weapons, has said it may charge the two boatloads of British sailors and marines with illegally entering its waters in the northern Gulf. Britain insists they were operating in Iraqi waters.
"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.
"They have to release them. If not, then this will move into a different phase," he told Britain's GMTV television.
Blair's spokesman said the next step London could take would be to publish proof, in the form of global satellite positioning (GPS) records, that the sailors had not entered Iranian waters.
"We so far haven't made explicit why we know that because we don't want to escalate this," he said.
British officials had shown Iran data on the sailors' exact position when seized, a British government source told Reuters.
Britain has been assured that the sailors are well but has not been given access to them or told where they are being held. British embassy staff will be allowed to see the sailors only once the preliminary investigation has been completed, an Iranian government spokesman told IRNA state news agency.
British Foreign Secretary Margaret Beckett telephoned her Iranian counterpart to demand the sailors' release and spoke "in very robust terms" to "again demand their safe and speedy return and immediate consular access."
Beckett cut short a visit to Iran's neighbour Turkey on Tuesday due to the seizure of the naval personnel, she said in a statement. Earlier, she said Britain would "continue to leave the door open for a constructive outcome".
Iraq's government and an Iraqi fisherman who witnessed the capture say it took place in Iraqi waters.
Iran captured eight British servicemen in similar circumstances in 2004 and released them after three nights.
Analysts have said the current crisis appeared more complex and would take longer to resolve than three years ago.
"The incident in 2004 was less tense, there were fewer gathering clouds, so they may well be held for longer," said Alex Bigham, of the Foreign Policy Centre. "There are probably also internal political battles in Iran over what to do next."
Some hardline groups in Iran suggest the case could be a bargaining chip in its nuclear and other rows with the West, exposing what analysts said were divisions with more moderate voices who want to build bridges abroad, not exacerbate tension.
In Iran, a crowd of hardline students chanting "Death to Britain" gathered on Tuesday on the shoreline close to where the Britons were captured and demanded firm action against the sailors, Iran's semi-official Mehr news agency reported.
But the official IRNA news agency suggested in a commentary the issue could still be resolved if London apologised.
In Moscow, Russian Foreign Minister Sergei Lavrov urged Iran to return to negotiations over its nuclear programme.
"The door is open ... I hope that a positive reaction (from Iran) will follow," he said.
- REUTERS
