Morgan Tsvangirai, the leader of Zimbabwe’s main opposition party, has vowed to keep fighting against the brutal regime of Robert Mugabe, as he left hospital in a wheelchair after suffering what he described as an “orgy of heavy beatings” at the hands of police.

Tsvangirai, the head of the Movement for Democratic Change (MDC), has been treated for what his party said was a suspected skull fracture since Tuesday, two days after he and scores of supporters were arrested in a protest against the president. He said the assault by authorities left him feeling as if he had been “partially decapitated." Doctors have not confirmed a fracture.

But despite his ordeal, he insisted said that democratic change in Zimbabwe was “within sight," appealing to the international community for help in overturning the regime. “They brutalized my flesh. But they will never break my spirit. I will soldier on until Zimbabwe is free,” he said.

The comments came as Britain stepped up its criticism of the president, accusing him of action “bordering on crimes against humanity” in his attempts to suppress dissent.

Yesterday, Mugabe told his critics in the West that they could “go hang” as he intensified a crackdown against rising opposition to his rule.

Human rights workers spoke of an “ad hoc state of emergency” in a large swath of Harare’s volatile southwestern townships, where hundreds of police were deployed, attacking ordinary people at random.

“The number of people being badly beaten up is very high,” said a private doctor who asked not to be named. “We’re only seeing a tiny proportion of it. People are terrified of leaving their homes at night.”

As opposition militants showed that they were prepared to meet violent repression with increasing retaliation, concern was growing last night that Mugabe may declare a state of emergency that would strip what is left of the curbs on him. Unofficial reports said that the issue had been discussed at Cabinet and in the politburo of his ruling Zanu (PF) party this week.

The southwestern townships have been the focus of a ferocious operation to squash dissent since Feb. 25, when police defied a court order to allow the opposition MDC to hold a rally. The move set off a violent reaction from opposition activists, culminating in the savage three-hour assault on Sunday of Tsvangirai and 30 of his lieutenants and supporters.

Images of the opposition leader entering hospital earlier this week, badly bruised and limping, fuelled international outrage and threats by the U.S. and other nations to strengthen sanctions against Mr Mugabe and his immediate coterie.

Following his discharge from the private Avenues Clinic, the MDC leader is expected to take rest at home. “He is still swollen and in pain, but he feels it’s better to recuperate from home ... he is still not himself,” a spokesman told Reuters, adding that Tsvangirai was still suffering from dizziness.

Writing in The Independent, Tsvangirai said the ordeal had made him even more determined to continue his campaign. “Democratic change in Zimbabwe is within sight. Far from killing my spirit, the scars they brutally inflicted on me have re-energised me,” he said.

“Of course we need the support of the world, and please do support us in achieving democratic change in Zimbabwe.”

He said he was assaulted after Mugabe “ruthlessly crushed” a peaceful prayer meeting organised by local churches, describing how he was beaten and verbally abused by officers after driving to a police station where senior members were being held.

“Upon my arrival at Machipisa Police Station, all hell broke loose,” he wrote. “I was pulled out of my car by heavily built men in police gear and they began smashing my head against the wall while pushing me inside the station.

“The orgy of heavy beatings continued once we were all inside the station. They were mostly targeting my head and my face. It was all like a bad dream. I felt like my head had been smashed open or I had been partially decapitated. I passed out three times, I was later told by eyewitnesses.

“I lost a lot of blood and was later injected with two pints. After passing out the last time, I can’t remember many things.”

In the U.K., Margaret Beckett, the foreign secretary, said that the "thugs" behind the violence needed to be identified and hit with further sanctions, calling for the United Nations to instigate tough action over human rights abuses and for EU sanctions — including an arms embargo, a travel ban and assets freeze — against the regime to be toughened up.

Writing separately in today's Times , she also said that it was crucial any measures taken against Mugabe would not harm Zimbabwean civilians — "the very people we are trying to help."

Lord Triesman, Foreign Office Minister, urged African leaders, including South Africa’s President Thabo Mbeki, to step up pressure on the Mugabe regime. He told the BBC Radio 4 Today programme: “(South Africa) are beginning to use tougher language than they have in the past, but I would dearly, dearly like to see them take a more forward-leaning position, of course I would.”

Defiant as ever, the president refused to bow down to global criticism of his tactics. “It’s the West as usual,” Mugabe said yesterday during a surprise visit to Harare by President Jikaya Kikwete of Tanzania.

“When they criticize the government trying to prevent violence and punish the perpetrators of that violence, we take the position that they can go hang.”

Western diplomats have linked Jikaya’s arrival with increasing alarm among African leaders that the situation in Harare was out of control.

“The African Union is very uncomfortable,” John Kufuor, the President of Ghana and the Chairman of the AU, said in remarks that were uncharacteristically blunt for an African leader. “The situation in your country [Zimbabwe] is very embarrassing.”

Doctors said that they were dealing with a constant stream of broken limbs and severely bruised and bloodied victims. Among them were six young women from Mufakose township who were dragged out of the shop they work in and beaten up because police said the red company logos on their T-shirts were MDC symbols.

The state media has blacked out all information on the assaults but Sikhanyiso Ndlovu, the Information Minister, made a tacit admission yesterday when he said: “Those who incite violence or actually cause and participate in unleashing it are set to pay a heavy price.”

Human rights organizations reported a continuing run of arrests in Harare yesterday, the second city of Bulawayo, the eastern city of Mutare, the central city of Gweru and the nearby industrial town of Kwekwe, some of them related to firebombing incidents in Harare and Gweru on Tuesday.

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