Iranian state TV says ten people were killed and more than 100 injured during protests in the capital Tehran on Saturday.

Authorities blame "terrorists" for the clashes, which happened as demonstrators again took to the streets to register their anger over the country's disputed presidential election.

Foreign Secretary David Miliband said Britain was appalled at the use of force against protesters and denied suggestions from Iranian President Mahmoud Ahmadinejad that the UK and US were interfering in the country's affairs.

"This can only damage Iran's standing in the eyes of the world," he said. "The blame being heaped on foreigners is no excuse."

He added: "The UK is categorical that it is for the Iranian people to choose their government and for the Iranian authorities to ensure the fairness of the result and the protection of their own people."

Foreign news organisations have been banned from covering street protests but there are reports of police using batons and live ammunition in Tehran on Saturday.

Two separate videos have also emerged of one incident in which a woman is seen bleeding profusely. One web posting claims she died after being shot.

The current unrest follows the government announcement that Mr Ahmadinejad defeated his reformist rival Mir Hossein Mousavi in nationwide elections on June 12.

Iran's supreme leader, Ayatollah Ali Khamenei, insists there was no ballot-rigging but protesters are demanding a re-run.

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