A video grab from footage shown on Iranian television on April 1, 2007, shows a man in a khaki uniform standing in front of a map of the Persian Gulf while speaking. Iranian television showed pictures of two of the 15 British sailors and marines held in Iran, and said they admitted that they were captured after entering Iranian waters.  [Reuters]

TEHRAN, Iran - Iranian state television aired new video Sunday showing two of the 15 captured British sailors pointing to a spot on a map of the Persian Gulf where they were seized and acknowledging it was in Iranian territorial waters.

Britain's Foreign Office immediately denounced the video, saying it was "completely unacceptable for these pictures to be shown on TV."

Adding to tensions between the two countries, about 200 angry Iranian youths chanting "Death to Britain" and "Death to America" threw rocks and firecrackers at the British Embassy and tried to rush the compound but were held back by police.

The 15 Britons were detained by Iranian naval units on March 23 while patrolling for smugglers as part of a UN-mandated force monitoring the Persian Gulf. They were seized  near the mouth of the Shatt al-Arab, a waterway that has long been a disputed dividing line between Iraq and Iran. Iran insists the sailors illegally entered its waters, but Britain says the team was in Iraqi waters at the time of their capture.

The captives first appeared on the state-run Arabic-language TV channel Al-Alam in separate video clips looking relaxed in military fatigues and pointing at the same map of the Persian Gulf.

The first sailor, who was identified as Royal Marine Capt. Chris Air, pointed with a pen to a location on the map where he said two boats left a warship of the US-led coalition in Iraq around 8:30 am on March 23. He said the seven marines and eight navy sailors were captured around 10 am.

Pointing to the map, he said "we were seized apparently at this point here on their maps and on the GPS they've shown us, which is inside Iranian territorial waters."

"And so far we have been treated very well by all the people here. They have looked after us and made sure there's been enough food and we've been treated very well by them so we thank them for that."

The second sailor, identified as Lt. Felix Carman, pointed to an area on the map and said that location was where he and the 14 others were arrested.

"I'd like to say to the Iranian people, I can understand why you are so angry about our intrusion into your waters," he said.

The newscaster said the two had confessed to "illegally" trespassing in Iranian waters.

Al-Alam broadcast longer videos of the Britons earlier this week, including footage on Friday of captured marine Nathan Thomas Summers apologizing for entering Iranian waters "without permission" and admitting to trespassing in Iranian waters.

He was shown sitting with another serviceman and the female British sailor Faye Turney against a floral curtain. Both servicemen wore camouflage fatigues with a Royal Navy label on their chests and a little British flag stitched to their left sleeves.

Al-Alam also aired video on Wednesday showing Turney wearing a headscarf and saying: "Obviously we trespassed."

Iran has also made public three letters purportedly written by Turney. The last letter contained an apology.

Britain has denounced the videos, calling them "propaganda" and "outrageous."

Iran's decision to air three videos on its Arabic-language TV channel, rather than on its main Farsi channels has not been explained. But it appears to be an attempt to seek support from Arabs in Iraq and the Gulf states, where many resent Britain's military deployment in Iraq and its historical role as a colonial power in the region.

Earlier on Sunday, British Defense Secretary Des Browne said his government was in "direct, bilateral communication with the Iranians." A Ministry of Defense spokeswoman said Browne was referring to letters and other contacts between diplomats, rather than any new face-to-face talks.

Browne, on a visit to Afghanistan, said Britain had "the support of almost the whole international community" in calling for the release of its personnel.

IS President Bush on Saturday demanded the release of the 15 "hostages." He said they were innocent and called their capture "inexcusable behavior."

Iranian President Mahmoud Ahmadinejad called world powers "arrogant" for refusing to apologize.

British Foreign Secretary Margaret Beckett appeared to soften rhetoric against Iran Saturday - though she stopped far short of an apology.

"I think everyone regrets that this position has arisen," Beckett said during a visit to Germany. "What we want is a way out of it."

In Iran, hardliners called for their government to remain firm.

The protesters at the British Embassy called for the expulsion of the country's ambassador because of the standoff.

Several dozen policemen prevented the protesters from rushing the embassy compound, although a few briefly scaled a fence outside the compound's walls before being pushed back, according to an Associated Press reporter at the scene.

The demonstrators hurled stones into the courtyard of the embassy. They also demanded that the Iranian government expel the British ambassador and close down the embassy, calling it a "den of spies."

Britain's Foreign Office said there had been no damage to the compound.

A British Foreign Office spokeswoman in London said diplomats continued to work normally inside the embassy and had not been at risk.