The warning from Foreign Minister Manouchehr Mottaki came as a senior Iranian diplomat said legal proceedings had begun against the sailors and marines for illegally entering Iranian waters but denied reports of a trial.

"British leaders should avoid media storms and politicisation to prevent a further complication of the affair," Iranian media quoted Mottaki as telling his Australian counterpart, Alexander Downer, in a telephone conversation.

The government of British Prime Minister Tony Blair has received strong backing from both the United States and the European Union, with Tehran on Saturday slamming the EU's "irrational" support.

"Iran rejects the EU's partial and meddling position in the 15 sailors' detention affair ... and urges European countries to refrain from impulsive and irresponsible comments," a foreign ministry statement said.

It warned EU leaders to avoid "uncalled-for interference in a completely bilateral affair between Iran and Britain."

EU foreign ministers at a meeting in Germany on Friday deplored the seizure of the Britons as a breach of international law and threatened to take "appropriate measures" if they were not released soon.

The EU move came after Britain on Thursday secured a UN Security Council statement on the Iranian action, but which was less strident than London had hoped for.

Tehran has so far refused to bow to mounting pressure to release the naval personnel, who are being held in a secret location and occasionally put on television allegedly confessing to and apologising for their transgressions.

Britain insists they were on a routine anti-smuggling patrol in Iraqi waters under a UN mandate but Iran says they were in its territorial waters.

Several conservative Iranian MPs and clerics are demanding the detainees be put on trial.

But Iran's ambassador to Moscow denied media reports originally from Russian television quoting him as suggesting the 15 might face trial.

"The network has made a mistake in translating the comments about detained British personnel and has reported the possibility of their trial," Gholam Reza Ansari told the Iranian state news agency IRNA.

In comments on the channel's Internet site, Ansari was quoted as saying "no kind of apology has been received from the British side and as a result the case has taken on a juridical form."

Earlier, IRNA itself had published what it said were excerpts from the interview in which Ansari was quoted as saying the British sailors "could go on trial for this illegal act".

But Ansari on Saturday said only that "the issue of British forces detention has entered legal proceedings."

Amid the public war of words, quiet diplomacy continued, with British Foreign Secretary Margaret Beckett saying her ministry had received and responded to a diplomatic note from Tehran, without elaborating.

"We would like to be told where our personnel are, we would like to be given access to them, but we want it resolved," Beckett said on the sidelines of the meeting with her EU counterparts in Germany.

Washington has rejected suggestions the Britons could be exchanged for five Iranian officials held by US forces in Iraq, while voicing its concern over footage of the captives making alleged confessions shown on Iranian television.

A Royal Navy serviceman, named as Nathan Thomas Summers, said in the interview broadcast on Iran's Arabic-language Al-Alam television: "I would like to apologise for entering your waters without any permission."

Britain has already frozen most ties with Iran, a move Tehran blamed for its decision not to free the sole woman detained as promised earlier this week.

Turkey, close to both the West and Iran, also said it was trying to obtain the sailors' release in order to avoid the crisis being used as a pretext for military action.

Ankara "has asked Tehran not to let the situation worsen and to free rapidly the British sailors," parliament speaker Bulent Arinc said in Lisbon, "in order to avoid any pretext for hostilities."

Both Britain and Iran have produced maps and global positioning system (GPS) coordinates to back their cases over where the sailors were when they were seized at gunpoint on March 23.