The crisis over the seizure by Iran of 15 British naval personnel has spilled into the streets. Hundreds of protesters gathered outside the British embassy in Tehran and threw firecrackers into its heavily-guarded compound. London said no one was injured and no damage was done.
The protesters called for the captured sailors and marines to be tried and punished. They urged the government not to give into international pressure to release them.
The United States and United Nations have expressed their support for Britain.
In Jerusalem, German Chancellor Angela Merkel whose country holds the rotating presidency of the EU said:
“I repeat that Britain has the full solidarity of the European Union on this issue. We demand the immediate release of the 15 soldiers.”
Iran says Britain should acknowledge its personnel trespassed in Iranian territory.
Speaking at a ceremony for the anniversary of the Islamic Republic, President Mahmoud Ahmadinejad said Downing Street should have apologised.
Earlier, it did seem Britain was trying a more conciliatory approach. There were reports it would guarantee the Royal Navy would never knowingly enter Iranian waters without permission.
But London insists its personnel were not trespassing and refuses to apologise.