Mr Mugabe has shrugged off Monday's unprecedented and unanimous decision by the UN Security Council to condemn the violence against the opposition and declared that a free and fair presidential election on June 27 was impossible.

M. Tsvangirai, who has withdrawn from the election and had been taking refuge in the Dutch embassy in Harare since Sunday, said Zimbabwe would "break" if the world did not help.

"We ask for the UN to go further than its recent resolution, condemning the violence in Zimbabwe, to encompass an active isolation of Mugabe," Tsvangirai wrote in an article in the UK's Guardian newspaper.

"For this we need a force to protect the people. We do not want armed conflict, but the people of Zimbabwe need the words of indignation from global leaders to be backed up by the moral rectitude of military force," he said.

"Such a force would be in the role of peacekeepers, not trouble-makers. They would separate the people from their oppressors and cast a protective shield around the democratic process for which Zimbabwe yearns."