March 28 (Bloomberg) -- Prime Minister Tony Blair stepped up a diplomatic push on Iran to release 15 U.K. sailors and Marines held six days ago, asking help from allies and saying Britain's boats were 1.7 miles inside Iraqi waters when the raid occurred.

``It is now time to ratchet up the pressure,'' Blair said in Parliament in London today. The capture of the U.K. personnel was ``wrong and completely illegal.''

The comments escalate the British effort, bringing details of the argument with Iran into the public. Blair had avoided a clash until now, attempting to defuse the situation through private discussions. A female sailor who was among those detained was shown later on Iranian television, in a move that was condemned by Blair's spokesman.

Even before the Britons were taken into custody, the United Nations Security Council was working to punish Iran for failing to cooperate with inspectors probing its nuclear energy program. The council voted on March 24 to freeze assets of a state-owned Iranian bank and impose penalties on military commanders.

``There is concern that Tehran will either try to put the personnel on trial or will seek a tough diplomatic bargain,'' said Simon Henderson, analyst of Near East policy at the Washington Institute. Another possibility is seeking ``some concession on the growing nuclear crisis.''

Iran maintained its version of events, saying in a statement issued by its London embassy that the boats were half a kilometer (0.3 of a mile) inside Iranian waters. At the same time, the embassy sought to ease tension and reassure the U.K. that its military personnel are being treated decently.

Female Sailor

``This legal and technical issue has no link to any other,'' the Iranian embassy said. ``We are confident that Iranian and British governments are capable of resolving this security case through their close contacts.''

The female sailor, Faye Turney, 26, will be freed ``within one or two days,'' Iran's Foreign Ministry said. Seaman Specialist Turney was held along with her colleagues on March 23 in the Shatt al-Arab waterway, which separates Iran and Iraq.

Turney, wearing a headscarf and smoking, said in the footage aired on Iranian television that her group had ``obviously trespassed'' into Iranian waters before their capture. The Iranians had been ``friendly and hospitable'' and had shown no aggression, she said.

Other members of the group were shown in the footage eating after their capture. The video was aired by Al-Alam, a Tehran- based Arabic language news channel.

`Clear Rules'

The U.K. government criticized the airing of the footage as a breach of the Geneva Conventions. ``There are very very clear rules about putting people in this situation on public display,'' Blair's spokesman Tom Kelly told reporters in London, before the pictures were screened.

Iranian Foreign Ministry spokesman Mohammad Ali Hosseini had earlier denied reports that the U.K. personnel would be shown on state-television. ``There is no need for this,'' Hosseini said in a phone interview from Riyadh, Saudi Arabia, today.

The dispute is stoking concern about conflict in the Middle East. Oil prices rose for a seventh day in New York, climbing close to $65 a barrel, on speculation that the confrontation may escalate and disrupt supplies.

British Foreign Secretary Margaret Beckett and the U.K. Ministry of Defence sought to build their case against Iran.

Vice Admiral Charles Style told reporters in London that Iran's navy ``ambushed'' Britain's boats on the Iraqi side of the Shatt al-Arab waterway. He said GPS navigation data showed the position of Britain's boats and that Iranian officials have given two separate accounts for the location of the vessels.

Nuclear Concerns

``It increases people's concerns about how they would behave if they had a nuclear weapon,'' said Beckett in a statement to Parliament. She is considering whether to take the matter to the UN and to European Union foreign ministers meeting this weekend.

Beckett ordered the Foreign Office to freeze all diplomatic activity with Iran to focus on the single issue until the dispute is resolved. No visas will be issued to Iranian officials, and all other government-to-government business will cease.

Britain has avoided threatening military action or increased economic sanctions against Iran. Beckett wouldn't be drawn into commenting on whether the hostage taking is a provocation, saying she told her Iranian counterpart that it is of ``grave concern.''

Blair's stance reflects his limited options to defuse the dispute and the lessons learned from previous incidents with Iran. President Jimmy Carter's effort to free 52 Americans held in Tehran in 1980 cost the lives of eight Marines and failed to recover any hostages.

Turkish Role

``Some people may think it's time to take the gloves off,'' said retired Rear Admiral Richard Cobbold, who is now director of the Royal United Services Institute in London. ``I'm all for being tougher if it produces the right results, but there's no indication that's what will happen. It could well end up being a mess with a lot of blood spilled.''

Turkish diplomats may meet with the detained Britons to help reassure the U.K. government that they are in good health, Turkish Prime Minister Recep Tayyip Erdogan told reporters in Riyadh today after meeting with Iran's Foreign Minister Manouchehr Mottaki at an Arab summit.

To contact the reporter on this story: Mark Deen in London at markdeen@bloomberg.net; Caroline Alexander in London at calexander1@bloomberg.net.

Last Updated: March 28, 2007 13:21 EDT