President Robert Mugabe stepped up his violent crackdown on political opponents today as heavily armed police stormed opposition headquarters and the offices of independent election observers on suspicion of plotting to overthrow the government.

Officials from the opposition Movement for Democratic Change said police beat dozens of members and arrested some 300 during the raid on its Harare headquarters. Material on vote-counting was seized from both offices.

The raids came amid a poll recount which observers fear is part of an attempt by the ruling Zanu-PF to cling on to power following March 29 elections. Mr Mugabe has so far refused to release the presidential results, and is contesting the parliamentary poll which saw Zanu-PF lose its majority for the first time since independence in 1980.

The MDC and the Zimbabwe Electoral Support Network, the country’s main independent election observation group, both claim that opposition leader Morgan Tsvangirai won the presidential vote, based on their own surveys of results posted at ballot stations.

In a statement, the MDC said 250 heavily armed officers had raided the building, taking away some 300 people including pregnant women and mothers with small children.

While some were staff members, most were supporters who had sought refuge in the opposition headquarters after being attacked by Mugabe loyalists, it said.

“Their homes were burned,” said Thokozani Khupe, an MDC vice president. “Some have been brutally assaulted.”

Officers also seized computers and equipment, and searched for key election-related documents, officials said.

Police said that the officers had raided the MDC’s offices seeking suspects responsible for post-election violence.

Assistant Police Commissioner Wayne Bvudzijena said he could not say how many people were arrested, but claimed they were responsible for “crimes that were committed in the countryside”.

No one was arrested at the observers’ office but police took files and computer equipment, Noel Kututwa, the group’s chairman, said.

Mr Kututwa said that police had wanted to arrest him and his deputy, Rindai Chipfunde-Vava, but both were away from the office. He said they were in hiding and claimed police were trying to intimidate the organisation ahead of a possible presidential run-off vote.

“They had a search warrant which stated that they were looking for subversive material which is likely to be used to overthrow a constitutionally-elected government,” Mr Kututwa reported.

Mr Mugabe has already accused the MDC of plotting a coup against him with the help of the British government.

The human rights group Amnesty International condemned the raids as “unacceptable” and called on the authorities to cease all harassment of political and human rights activists.

The raids came the day after the top US envoy for Africa, Assistant Secretary of State Jendayi Frazer, declared Mr Tsvangirai the clear winner of the presidential vote, basing her conclusions on results compiled by the ZESN.

Earlier this week, a group of Zimbabwean church leaders warned of full-scale genocide unless the international community intervened. The opposition claims that Mr Mugabe is waging a campaign of brutal suppression which has killed at least 10 of its supporters. Government officials have in turn accused the opposition of perpetrating violence.

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