His head swollen and showing the signs of a deep wound that required ten stitches, Zimbabwe's main opposition leader appeared in court this morning, two days after he was arrested with 50 others at a prayer meeting outside Harare.

Witnesses in the court, including the British Ambassador to Zimbabwe, said Morgan Tsvangirai was limping and his head was partly shaved around the gash which his supporters say is evidence of an attempt to kill him on Sunday.

"The right side of Morgan’s face was swollen as was his eyes, which were bloodshot, but he seemed coherent. It was damn barbaric," said Andrew Pocock, the UK envoy.

Riot police then cleared the court, ordering only those accused by the authorities of "inciting violence" to remain. After the short hearing, at which no one was charged, 14 of those detained, including Mr Tsvangirai, were taken in ambulances and private vehicles to hospital. One person had to be carried on a stretcher and another woman could barely walk. They remained under guard.

Lawyers for Mr Tsvangirai and his Movement for Democratic Change (MDC) have accused the Zimbabwean authorities of beating and torturing dozens of opposition activists after their arrest at the rally in the township of Highfields on Sunday. One man was killed in the unrest.

Their detention and heavy-handed treatment has prompted broad international condemnation of the regime of President Robert Mugabe, which is battling a growing economic and political crisis in the country.

Today Condoleezza Rice, the US Secretary of State, demanded the immediate release of all those detained and said that the attacks and arrests showed that Mr Mugabe's rule "is ruthless and repressive and creates only suffering for the people of Zimbabwe".

The UN High Commissioner for Human Rights, Louise Arbour, called meanwhile for an immediate investigation into the arrests, saying: "This form of repression and intimidation of a peaceful assembly is unacceptable, and the loss of life makes this even more disturbing." The German presidency of the EU accused Mr Mugabe's government of "criminalising" a peaceful protest.

Even South Africa, perceived by many observers as the only country able to exercise any real leverage over Mr Mugabe and frequently criticised for failing to do so, was moved to urge the Zimbabwean Government to abide by the rule of law today.

But Aziz Pahad, the Deputy Foreign Minister, also appealed to Zimbabwe's opposition groups not to inflame the situation and "work towards a climate that is conducive to finding a lasting solution to the current challenges faced by the people of Zimbabwe".

Mr Tsvangirai's legal team said that prosecutors in Harare's High Court had not filed any charges today but intended to indict the opposition leader for inciting violence. No bail was granted to any of those arrested on Sunday, although they were allowed to receive medical care.

Earlier today, a High Court judge ordered the police to charge Mr Tsvangirai and his supporters by 10am (GMT) or let them go.

Despite the international pressure, the Government has shown no signs of easing its stance on Mr Mugabe's critics.

Zimbabwe's Home Affairs Minister, Kembo Mohadi, told the state-run Herald newspaper today: "We are not going to be found wanting. We will enforce the law to its fullest... Police could not just stand by and see the country go on fire so we deployed and managed to quell the disturbances."

The newspaper also published photographs of police officers injured in Sunday's clashes and, in an editorial, blamed the opposition for further destabilising Zimbabwe at a time when chronic unemployment, hyperinflation and state repression are all combining to undermine social order.

"We unreservedly condemn the state of violence unleashed by the MDC ... Tsvangirai should be ashamed of himself," it said.

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