Zimbabwe's opposition party leader Morgan Tsvangirai has been arrested as African leaders gather to debate the escalating crisis in the country.Mr Tsvangirai, who was badly beaten after an earlier crackdown this month, was among a number of Movement for Democratic Change officials held when police entered the party's Harare offices.The MDC said Tsvangirai had been due to hold a news conference "on the escalating and systemic campaign of violence and intimidation" by President Robert Mugabe's government.The raid looked likely to increase pressure on African leaders to use a special Tanzania summit to censure Mr Mugabe, who has faced a volley of criticism for violently cracking down on opponents of his 27-year rule.Foreign Secretary Margaret Beckett was among the first to criticise the latest arrests, saying: "I strongly urge Mugabe and the Zimbabwean regime to heed the calls made by so many of the international community and their African neighbours to stop the oppression of the Zimbabwean people and respect their human rights."EU president Germany said it was "deeply concerned" at the arrests and demanded access to Mr Tsvangirai and other detained opposition politicians.The special two-day Tanzania summit will be a test for the 14-member Southern African Development Community, accused in some quarters of not flexing its muscle against Mr Mugabe's government.© Independent Television News Limited 2007. All rights reserved.