British Prime Minister Tony Blair urged Iran on Sunday to release 15 British sailors and marines who were seized off the Iraqi coast on Friday, calling their detention "unjustified and wrong."

The group and their two inflatable boats, which were being used in a search for smugglers, were seized at gunpoint on Friday at the mouth of the Shatt al-Arab waterway, marking the southern stretch of Iraq's border with Iran.

British Prime Minister Tony Blair insisted on Sunday that the 15 captured British sailors and Royal Marines had not been in Iranian waters.
(Kai-Uwe Knoth/Associated Press)

British diplomats, including Ambassador Geoffrey Adams, met Sunday with Iranian officials in Tehran, where their demand for access to the detainees was denied, after Iran refused to confirm exactly where they were being held.

On Saturday, an Iranian general, Ali Reza Afshar, said the eight Royal Navy sailors and seven Royal Marines were brought to Tehran for questioning and claimed they had "confessed to illegal entry into Iran's waters."

"It is simply not true that they went into Iranian territorial waters," Blair said at a news conference in Berlin on Sunday, calling the situation "very serious."

He said "there is no doubt" they were taken while in Iraqi waters.

"I hope the Iranian government understands how fundamental an issue this is for us," he added.

The British prime minister said he hoped the issue could be resolved over the next few days, "but the quicker it is resolved, the easier it will be for all of us."

Tense relationship

The capture of the British service personnel risks escalating an already tense relationship between Iran and the West.

The UN Security Council on Saturday agreed to moderately tougher sanctions against Iran for its refusal to meet UN demands that it halt uranium enrichment.

The sanctions include a ban on Iranian arms exports and freezing the assets of 28 additional people and organizations involved in Iran's nuclear and missile programs.

Speaking to reporters at the United Nations in New York, Iranian Foreign Minister Manouchehr Mottaki said Blair was wrong to say the British sailors and marines were in Iraqi waters when their boats were intercepted by Iran's navy.

A journalist from the Times of London newspaper asked whether they could be charged with espionage, and the minister said it's a possibility.